[Tom I]

1/4-20 is the way to go for our team. It's pretty much the standard for everything, with only a few 10-32 exceptions, and even fewer 8-32's. Personally I always like to have a 7/16" hex head, as we have dozens of 7/16" wrenches for standardization purposes. We also use allen heads, as we have a 3/16" standardized allen wrench as well. Torx really has no big advantage in the grand scheme of things other than impossible to find a driver for, so we just don't use it.

The biggest thing I would say is to standardize. Pick a system and go with it.
Oh and whatever you do, whenever possible USE LOCK-NUTS!