I love little chameleons- but unless you go wild caught they are pretty hard to find and it's probably not a great idea for a first chameleon- (wild caught that is)
There are a couple of people who are forum members working with sternfeldi - which is the chameleon that gets sold in the US as rudis. There are more members who work with lateralis also known as carpet chameleons- I waited for almost a year to find my flapneck as a captive born- and paid double but I think it was worth the extra as she's been healthy and active since day one. Most of the wild caught ones don't seem to make it for very long-
Your best bet is to get do as much research as you can and keep an eye on the classified here-