There must be a lab in the state capital that can process the film dip and dunk for you, if not even closer to you. Have you tried the Yellow Pages for a local lab? If nothing else, "word on the street" is that when Wal-Mart receives medium format film for processing, they send it to an honest-to-goodness Fujifilm U.S.A. lab for processing. If that really is the case, it couldn't be that bad of an option.
Not to stray off topic too much, but I would really not use Ektar for senior portraits, unless it is going to be purposefully contrasty and saturated. Heck, I don't even like it for most landscapes, where many people seem to love it. I like it for certain still life pictures (purposefully garish ones), and that is about it, for the most part.
Additionally, the process for Ektar is no different than for any other color negative film. It should name the process right on the backing paper or film cassette, so lab techs know what to do with it. Based on threads here on APUG, many lab owners seem to have told customers that it needs special processing, but this is just not true. So, while I definitely recommend quality professional processing, it does not need to go to a special lab just because it is Ektar.
I am also not sure medium format is warranted by the situation. I think 35mm would be just fine. The quality of modern films is outstanding; 35mm can be pushed quite far. And let's face it: yearbook printing is not going to be top notch anyhow. It will mask any advantages medium format might have.
It helps to filter all color films, even negative ones, in off-colored lighting. But because Ektar is contrasty and saturated, it is even more important with this product than with many other color neg films. For light open shade, I'd at least use one of the heavier 81 series filters. For deep shade, I'd go all the way to an 85+82 filter combination. Overcast weather will play hell with this film too.
My high school senior photos were shot in a studio on sheet film. If I recall correctly (big if) it was 5x7. The prints were color, but I have no idea if it was negative or positive film. I knew next to nothing about photography at the time, but I loved shooting my 126 instamatic. I'd never seen or even heard of view cameras or sheet film or sheet film holders before. I recall grilling the photographer constantly throughout my sitting.
I have heard of complaints of shadows going excessively blue on Ektar, and have seen it myself in some prints I have made but accepted it because the shots were on a sunny day and the blue skylight would be expected to cause some blue in the shadows. Add to that the fact that Ektar is a high saturation film, and this would cause the blue in the shadows to pop out just like everything else. That is my theory of why some users are reporting this. Someone correct me if there is a reason why this wouldn't be so.
The characteristic curves on Kodak's website show the yellow layer curve to be slightly higher in contrast than the magenta and cyan, so if anything this should be causing the shadows to go yellow. But I know of no one reporting that. Perhaps Kodak deliberately designed the film this way to help minimize the blue in shadows.
In addition to all the "Ektar isn't the best portrait film" replies (adding that both of the new Portras are excellent, assuming you want to stick with Kodak), I should add that "scanning and attempting to get good skin tones off C-41 is really hard if you haven't done it before" and that I personally find Ektar much harder than other films to get good skin tones from a neg scan. So you might want to avail yourself of your lab's scanning services, at least for that one important shoot.
If you're shooting portraits of you're son I recommend the new Kodak Portra 160 rated at the boxed speed, the colour palate and skin tone rendition are superb, Ektar is a wonderful extremely sharp and saturated film that great for general photography, but would not be my first choice for people pictures.
Ektar isn't garish and balances skin tones when you colour balance the film. It's more realistic than Portra which fiddles with the colour to give you a wide range of colour balance/grading options while prettying up someone's skin.
I once read the argument on here something along the lines of Ektar making someone's face really red and patchy - they were referring to an old weathered face that was in reality like that, where as they said Portra didn't do that and gave normal looking skin <- In which case Portra didn't give normal looking skin as the subjects skin didn't actually look like that, where as Ektar faithfully reproduced the flaws.
If your skin tones on Ektar are close to real life saturated red objects your colour balance is way off.
They're no where near a saturated red subject.
Me Aerial Filming by athiril, on Flickr
If you're doing something like trying to shoot nice smooth portraits in hard lit direct sun conditions with harsh shade across a face, then I would think bigger differences would be had by working on your skill and knowledge as a photographer.
Ektar 100 is a great film, and I have had good results from both Dwains photo, and Milford Photo with 120 format when I had it processed and scanned by both of these places.
Something I have not had good luck with when using Ektar 100 is scanning myself. I don't know what equipment you have, but if your thinking flatbed scanner at home think again. Let the people that do it all the time and have the right equipment that gets calibrated regularly scan this film for you. Having the lab scan the film is only a few dollars and we are talking about a handful of rolls that you will only be shooting for this once in a lifetime event. If you don't like the lab's scans you can always scan yourself, but once you get your film from the lab it is a lot harder to get them to scan it.