1 you can dye the leather good luck.
2 sound deaden the pieces. If you dont have experience with fiberglass i suggest you practice on small pieces first.
3 dual exhaust+four banger = no no no
4 springs and lowering struts. have fun its almost he smae platform as the cavaliers and sunfires so it wont be easy(or maybe the grand ams?)
5 are you buying this for the need or for the cool factor. If its the cool factor you may want to look into a cheaper cool factor. breaks are major change.