Most people think they are in poor taste, or that modifying should be left for performance. Others think you shouldn't mod your civic at all. Actually, I don't mind people putting them on, although you will get some haters. To each his own, I say.
You can find them all over ebay or do a search for honda and performance parts, there are a bunch of sites online that sell these parts.
Just hunt around on ebay for some factory ones. The RSX is a nice looking car it would be too bad to ruin it with cheezy tail lights.