I think a euro-style wheel would suit the car properly. Something like OZ, BBS or Borbet or something. I would avoid painting stock wheels - if you can get around it, never modify stock parts because you never know when you might have to sell it in stock form or whatever.
5x108 can be a tricky pattern, but you'd be surprised what is available. But as usual, I think you should wait to buy something until you're prepared to pay for an up-market product, something high quality from a respected brand with a history of performance and quality. They're more expensive, yes, but good things cost money. I could have had my Rex loaded to the gills with cheap parts by now, but I insisted otherwise. It just so happens nobody makes cheap parts, lol, but you get the point.
18x8 +40, $380