I run a caterham here in Dubai. Great fun it is too (and I say that having had more than my fair share of unrepresentative problems with mine(. There are plenty of others, a westfield or two plus a few GTS's. Don't think there are many that are run as main cars though. Speed bumps are generally okay if you're careful, although I have cracked my sump before now when I didnt spot one before it's too late. The heat is the biggest problem though. Too hot for me (and I am, as a result of a previous head gasket failure, paranoid about mine overheating) but you may be made of sterner stuff.
Gulfsport have the regional franchise and if you want a new one you have to go through them (Caterham won't supply direct out here). Parts are generally not a problem - Gulfsport can supply (although they don't maintain stock) or you can order from Caterham direct. Many parts are made by other car manufactuers and so available locally (e.g. from Al Tayer for engine parts, which tend to be from ford). They're generally dead easy to work on too, relatively speaking.
Second hand ones crop up from time to time out here. From another thread it looks like another member (bigmac?)picked up a cheap GTS recently, and I think Jason at A2B may be looking to sell his too. I'm a big fan of doing the build yourself though.