I am familiar with the Steeda equipment and have their current listing of upgrades. I would use Steeda equipment and feel comfortable with it. I would be a bit dubious as to their claim of 30-40 WHP and suspect most of that accrues to the tune.
Re: exhaust, I'm not saying that $1,000 should not be spent, but that the original post had a limit of $2,000 and if I had to live within that, the aftermarket exhaust would be last on my list of power enhancers. Could you provide me with a link to prove the statement regarding "sound 100% better, look 23.5% better...". I suspect those figures are not verifiable. Sound 100% better? Come on!! That's a very inflated and totally subjective call on your part.
There are no performance mods included in the GT/CS to my knowledge. The "hefty fee" was $2200 on my car, and includes: 235/50/ZR18 rubber, 18" premium alum wheels (the polished Bullitts), two-tone leather seats, different front/rear fascias, and 5 minor appearance items.