I have a 07 Dodge 1500 SLT. In your opinion should I get Cowboy exhaust (where is comes out at a 45 degree angle) or straight (where it comes straight out the back)?

 

Straight. Looks much better and the tires don't throw near as much crap on the tips.

 

i like straight but really it depends what you plan on doing with the truck
if your hooking and unhooking trailers alot the cowboy would be better less exhaust in the face
and straight is a bit quieter

 

I want to run a single tip out the passenger side in front of rear wheel.

I'm not a fan of the straight exhaust but it is a matter of personal preference. Seems like people inevitably back into something and then one pipe is cockeyed and looks funny.