Instead of modding further why not go through the whole car and see what needs either replacing or repairing, I have looked at mine and Im gonna under guard the underside of the car to prevent any rust and what not, clean up suspension arms and paint and do all the silly boring jobs so the car stays crisp top and bottom, change hoses and little bits and bobs.
I have only seen your car once at blue water so dont know much about you but little things dont need to cost alot and it may put further idea's in your head whilst your doing the boring jobs.
oh and only suttle decals will look good, maybe using the lower part of the car where the fold of the car is infilling it with some sort of cool design, some cars just look to chav when they are all decalled up.