My favorite sources for sans online have been Bob Smoley's Gardenworld, Grigsby's, and ebay. Bob Smoley has a huge selection but unfortunately no pictures and limited descriptions. I think his prices are pretty good and I have always gotten nice plants from him but give him some time to fill orders because it seems he does everything himself and it sometimes takes quite a while for him to ship the order out...worth the wait though.
Ebay is cool to get some unusual sans but you sometimes have to watch the prices as the bidding gets out of control at times but other times you can get some good buys. Nice thing with ebay is that you can see a picture , usually of the very plant they are shipping to you with measurements etc so no surprises when they arrive.
There are other sources that some others have mentioned but these are the 3 that I have had good experiences with. If you check around this forum you will find mention of others such as Glasshouseworks but I have not dealt with them so can't really recommend them myself.
As far as your sun question goes , I can't really help with that because your sun is so much more intense than what I deal with here. Some of them do well with alot of sun but maybe someone will chime in that deals more with the kind of intense heat and sun that you do.
logan

You have an expert right there in LV. His name is Dave Turner, and lives right off of Cregg Road and Rainbow. I think is wife's name is Lisa but I will not guarantee it. It has been over 20 years since I left Vegas and can not remember. I saw Dave at the Fall Flower Show and Sale last year.

He does not do mail order, but call him and see what you can work out. I don't have a Vegas phone book or I would look it up for you.

By the way, try to take in the fall show. It is October 22 at the Garden Club building on the west end of Lorenzy park. I'll be there judging the show, maybe I'll meet you there.

Betty