Imo save up another 100 bucks and find a set of gtp injectors I think Mike Morris even has a set. They cost roughly 100 bucks and flow 42lb. Then you can have both the intake and injectors, if you do one and not the other chances are in the future you will need/want the other and will have to pay to get it retuned. Whatever you want to do now just save up to get it all at once.

An ls1 intake is a huge bottle neck for that combo, even an ls6 is really but short of a fast which is what that combo needs it's the next best thing.

 

The LS1 intake strangles even a stock motor. As stated above, it's the very minimum you must do with your combo. Unfortunately for you, this is not an either/or situation, but both/and. Thankfully you've gotten some good guidance on inexpensive injectors. Then of course when it's all together, it's tune time.