First of all, welcome to Automotive Forums.
My one friend works at an auto store and he told me that when you buy kits from sites like andys autosport that you actually get low quality fiberglass kits. How accurate this is, I don't know. But its definetly something to ponder on if your going to be spending that much money on something. As far as fittiment(sp?) issues, it should fit fine with the car lowered. Although once its all on you may have to raise it up a bit to avoid bottoming out on speedbumps and such. The motegi wheels, I'd check the prices on tirerack.com and ebay.com those would be your two best bets for getting them cheaper than usual. The paintjobs gonna cost ya a bit. I'd say you'll have about 1000 or so in full repaint. It all depends upon who does it and the quality of the paintjob. I'd go with someone reliable that knows what they're doing. Once again, another spending that much money for quality issue... Hope I helped ya out some.