How about faster lenses?
I like primes and use a 55mm f/2 most of the time. Trying to lay my hands on a nice 85mm f/1.4 when I can, and a 50 f/1.4 or so. Those extra stops are worth a lot.
And shooting ISO 400 film at 640 isn't going to destroy the picture.
Have fun. I saw your intro too. Welcome to APUG!