At risk of starting a brand war, let me suggest you try fuji astia 100f or provia 400x, with a mild (half stop or so) underexposure if you really want more saturation in the primaries. Better yet, just bracket in small steps and see what you like.
On one site, the front page for "color reversal films" was 2/3 Fuji and 1/3 Kodak (approximately). So, I can agree with what you said. In fact, the only reversal film in my freezer at this time is Fuji!
And, they are not hard to find. Adorama, B&H, and Freestyle all feature reversal films with Kodak there along with Fuji.
I found some E-6 films on some retailers, but in fact i am trying to find slides for 4x5 and i hardly can find only 1 or 2, I was hoping to find Velvia 50 and i couldn't, not impressed for Astia, and i was hoping to get Velvia over Provia, and E100G was available few days ago and suddenly out of stock, it may be in stock again but when and where i have to keep searching.
Lucky that i bought some films in 120 formats due to discontinuation.
I did some calling around today RE: Kodak 4x5. Though I heard a few different things, the one thing I heard over and over was that Kodak has discontinued E100VS in 4x5. E100G is still listed as available but on back-order from Kodak (all 3 distributors said that, too.) Theories tended towards Kodak doing a single E-6 film (similar to the Portra 400 NC/VC becoming Portra 400.) Doesn't really help too much, but hopefully this will be seen as it was intended--information. All I can say for certain is that if you like E100VS in 4x5, maybe pick up some while there is quantity out there and before the official discontinuance is announced.
"Everytime I find a film or paper that I like, they discontinue it." -Paul Strand