tri-x 400 should treat you well. very well.
i am shooting a roll of cheap expired colour film right now for both of them to test metering and stuff, but they seem alright.
also, with film photography, i guess it is a lot of hit and miss, especially if you are used to having a dslr where you can shoot in almost every light, as with film, especially with iso 100 or so, its harder since shots at 1/50th that would be perfectly fine with digital can go horribly wrong..
also, depending on the kind of canonet you have, they can be kinda soft wide open, but there are a few amazing ones.