I don't know much about the area (I live in Europe...) and thought I'd ask here if someone had some advice, primarily on were to go. The main target is finding and photographing rattle snakes, but horned lizards and (especially) the Gila Monster is high on my list. Otherwise we are interest in all sorts of herps. If someone could give me some ideas of what places would be worth considering I'd be thankful.
Since I haven't been active here I will also show a few of my photos (not the best I admit, but I'm still working on by technique. I've also started to use lightroom now).

Bothriechis schlegelii, Corcovado National Park, Costa Rica

Trimeresurus wagleri, Bukit Lawang, Indonesia

Chrysopelea pelias, Central Catchment Nature Reserve, Singapore

Boiga dendrophila, Central Catchment Nature Reserve, Singapore
Cheers!