i was wondering if ITR suspension would fit on an LS..if so would this be a big difference/worth the effort? or what would be a best bang for the buck suspension coilover set up

 

It would fit but you would need the ITR's rear lower control arms as well. It's essentially the same car.

Whether or not it is worth is it up to you - how much will it cost you? what are you looking for out of the car? Could you get some nice lowering springs for half the price?