What 18's and tires are people running

Well it's time for new tires for my boat and been debating swapping to 18's.
I've got 5x4.5 bolt spacing and have 8" of clearence between the hub and springs, brakes, etc.
Was wondering if anyone knew of any vehicles wheels would work or where everyone is getting there wheels. Also what tires would I have to run seeing as the weight of my vlx is much more then the normal fwd car that the size tires would normally go on.
I know there are lots of pro's cons to this but I don't want that speach. Just looking for help as to maybe find a used set of custom wheels and get the correct tires for my boat.