Iwould get some different brands and weights and let the gun tell you what it likes.A 250gr bullet can drop a deer on the spot just as easily as a 300gr bullet,it is the shot placement.As far as kick I have shot 245-348gr powerbelts and 250-300gr shockwaves and didn't notice a hole lot of difference in the kick.
Mabey Cayugad could shed some light on this subject for you as he has a lot of experience with a lot of different guns.