3.5 v6 turbo or supercharger?
 

I've been doing research and cant find any kits specifically for this. I read some other threads similar to this but want to understand fully what I need to do. If I get an STS turbo would it work? Are there any turbos Or superchargers I can get without hardly any custom work to it?

No it's not

IMO your best bet for your 300hp goal given the criteria you've laid out ($2k max budget, hardly any custom work, don't want to sell car, etc) is nitrous. You can get a rather complete kit for $1k, and the shot size is reasonable to hit 300hp. You can save the rest of the money for nitrous fills.

If you had fab skills (tube benders, welder, etc)- you could probably build a turbo kit for that price, but judging by the way you're asking the question, I'm assuming you don't.

If you wanted a more reliable 300 hp in the same type of car with minimal modification, I'd strongly suggest looking at a GP GXP, Impala SS, or Monte SS with the 5.3L. Between what you could sell your car for and the $2k, you'd be able to pick up some kind of 5.3L Wbody. You'd have to break one of your criteria, but at least you'd be able to keep the rest (budget, little/no fab work, etc).

I agree with bumpin