Invite me over and I'll give you a few ideas on the way I designed mine. This is my third darkrom and I've made lots of mistakes in the past. Send me a "personal message" and we can work our schedules.
I'm glad I got a floor-standing Durst... I'm hopeless at carpentry ;)
I built my dry area table using the design mentioned in "Build Your Own Home Darkroom" by Lista Duren, et al. It was quite a simple task and all I needed were - 3 - 2x4s, 2 - 1x6s, and a 4x8 sheet of particle board, in addition to 4" deck screws and nails. I use it to hold my 35mm enlarger and various dry side "stuff". It is very sturdy and should hold a 4x5 enlarger as well.
i have built 2 different enlarger tables in the past, and both worked really well.
ann's idea of using sawhorses works great. at the same time you buy the sawhorses, buy a door, put the door on the horses, and it'll hold a ton of weight. i had a little durst and a omega d3v on it and no problems.
the second table i built is the one i use now. 4x4 legs cut about 32.25" high, 2 - 2x3 or 2x4 as braces between each of the legs - and 3/4" plywood as the top. i also have a few 2x4 "on edge" running underneath the table to brace the top. i have both the enlargers i mentioned before on it, as well as a huge . auto omega e4.
i have a bunch of other odds n'ends ( read : JUNK ) on the it now too, and this table keeps begging me putting more "stuff" on it :)
for the vent - if you don't mind something on the side of your house / building that looks "industrial" -you might consider getting one of those grey-metalic louvered (outside window) white grill ( inside window ) window fans that nutone makes. i think i picked one up a while back for $60 - $70.
kind of makes you feel like you are in a photo-factory when you have it up n'running, and is always a conversation piece ... :)
good luck with your project!
Aggie, just a thought, but I have an old school desk that I've used for years. It's the old primary school steel and formica top kind (the one with the ink well in the top right corner). Weighs more than 6 grade 5 students all together. Very sturdy but I can't get my knees under it now (I'm 6'4").
For my first darkroom, I'm going to use an old back of drawers cabinet that I have in the garage now. It has a missing cutting board slot on the top row, and a pretty average size drawer below that. I'm going to convert that top drawer into a paper safe ala some of those darkroom books.
For stability, since I'm next to a very solid concrete wall, I'm going to take and the drawers out and mount the whole thing through the side to this wall. I may have to add a piece of plywood to the back for lateral stability, depending on the shape of the cabinet after I try to move it downstairs!
I like the suggestions about wall mounting though. I think I've seen some photos of someone who mounted the enlarger on the wall, and had the base board on adjustable mounts. This would be pretty cool, but I would think that you would have to be very careful to maintain proper alignment etc.
Have you guys ever mass posted your own dardrooms in the gallery for us newbies to drool over? I saw two or three there today, but the more the better! Thanks.