Go with the 255 fuel pump and go with a set of 370cc not 310cc, with 310cc your injector duty cycle will be a little on the high side and if you ever decide to push your compression up a little in order to get those cams to make power, you'll need the extra fuel. Besides, it's never bad to have a little too much rather than too little. But yes, you will need to change out your valve train, amongst a couple other things in order to run the stage 2 cams.

Good luck,
Aj