exhaust question

    Is there a big difference from buying a cat back exhaust as opposed to buying a muffler and having a shop do the pipes?? 

   Also how about a straight pap (oops meant pipe) from the cat?  Instead of having the bend.  Would that be a good idea?  Trying to get an idea so any help would be appreciated =)

If it's a good shop you use..the only differance would be cost and easy of install. A full cat back might be a bit more expensive, but can be done by yourself in usually an hour. If you have a shop do it the only thing you really need to make sure is that they use mandrel bends in the pipe, not crush bends.
 
Now a straight pipe would be more effecient than a pipe with bends...only thing you'd have to do is find a way to install it that wouldn't interfere with other components and wouldn't drag on the ground.