After lid then what?
 

I currently have an ls1 with slp lid, holley filter, flows and soon a cutout. I do not want anything big just yet because it is my daily driver. Would a catted y be something good?

Gaines from just a y-pipe at this point from what I hear is going to be pretty minimal. Do the y-pipe at the same time you do some long tubes :D

what are your goals with the car?
I would be thinking along the lines of suspension and or tires if I were you just because these cars are large on power and small on traction.

agreed with psycho

any one of the following or combination of them:

lower control arms
strut tower brace
subframe connectors
sway bars

will all make the car handle better and more enjoyable to drive

I agree with waiting to get the Y pipe. Don't get a STB. I didn't notice any difference at all with a STB on my car. I think SFCs are the way to go.

Get some springs to, these cars come from the factory with the Z71 package :D