Personally, I don't use blasters. Your main character will have his/her first lightsaber by the end of the first (or third depending on how you look at it) planet, so theirs not a whole lot of time to work with blasters. But, assuming you may want some of your party members to use blasters, here are some good ones:
Zersium Rifle
Zabrak Blaster Carbine
Verpine Droid Disintegrator
Onderon Repeating Carbine
Heavy Repeating Carbine
As for feats, just max out:
Sniper Shot
Power Blast
Rapid Shot
Percise Shot
I think you may be wasting your time with all this though, because like I said before, you have your first lightsaber before you're half way through the game. Use melee weapons, they look cooler anyway.
Hope this helps...