Best route for next upgrades

[Rex 2.0]

I have a bit of money from working lots of over time the past couple weeks and I want to get a couple of parts for my car. I have to get a passenger side lower control arm becuase mine is shot($150 gmpartsdirect).  I figured i would get the under drive pulley and dog bone mount from ffp($200). It should not take much time because everything will be torn apart already. I plan on putting in a 3400 this summer so I want to stick with stuff that will transfer over.  I was thinking of taking it some place to get a high flow cat and new piping put on.  I was kind of think duals. Mine is getting rusty and starting to sound terrible. I am guessing this would cost around $600.  I would do it myself but I don't know how to weld and I hate clamps.  

Any feedback is much appreciated. The faster the better I like to spend money.

[Asylum]

You can get a perfectly good lower control arm for ALOT less than $150 from any good Junk Yard.
Other than that sounds OK.
Duals don't make any power at all, but they do look good if done right as long as you don't have factory GFX

[IsaacHayes]

Keep in mind if you get a control arm from a junkyard you will likely need to rebuild the rear vertical style control arm bushing.

I've done mine twice. Cut out the rubber, cut the metal ring that's pressed into the control arm with a haxsaw, dremel out the rust make it clean. Then press a new bushign in using a bench vise, just a little at a time back forth around the bushing until its all the way in.

If your arm isn't bent/damaged and your problem is the bushign you can rebuild your exsisiting one.