To get the bumpers painted properly would cost a fair whack.Can you not find a pair in same colour in good nick.What paint code is your car ?.There are some people about who will do it for a reasonable price but often the finish does'nt last.You get what you pay for 99% of the time.Paint is not cheap,labour for prep is also costly.
Coilovers need to be fitted properly,lot of cowboys out there.Cheap coilies are harsh !.Change all your top mounts at the same time though.
Exhaust is'nt a major hassle but some aftermarket one's need spacers on the brackets so they clear everything and don't melt the rear bumper.Make sure you get the right one as some early MK3's have a shorter cat so the middle section is longer than the later models.