get both. res cut is a maximum of 50. if its more then that look for another shop.
u can find res cut from range of 25-50.
windows should be around the $200 area, it matters what tint u get.
im going to get 30% slightly mirrored. (comes out looking like a brownish mirror) so it matchs my car better. i have a champagne color contour(that biege/silver metalic)
but if u can only get one, cut the res, and get k&n drop in or a kkm cone.
or u can get rid of the rear muffler and leave the res, and run a pipe from the res to the bak end of the car.
thats what im going to do when i put on my svt body kit.