If you can do it yourself you can 'upgrade' right now
-- Exhaust isn't difficult to replace,.. it just is ALOT easier on a lift,.. and with the right tools (cutting devices) , impact wrenches etc.
Personally I would just get from headers (after headers) back to tips aftermarket. Bring it to a regular exhaust shop and have them cut the old, put in the new.
This will keep you under a grand, and you'll have much prettier, better sounding, more fuel efficient (hopefully), and more horsepower than the stock exhaust.
In other words, getting only the Cats done at the dealership (despite if its part of a larger piping) -- Is going to cost you much more than a complete aftermarket Cat-back (only including cats this time) system aftermarket at an indie exhaust shop -- (as opposed to the dealer) .
So start shopping for exhaust, .. exhaust doesn't automatically mean 'loud', 'unruly' or 'ugly and non factory looking'. You can get aftermarket that looks indentical to your current exhaust and is just as quiet.. (but flows a tiny bit better).