Hi Ali
Welcome aboard!
I'm afraid you're probably going to have quite a search to find A/C in Charloteville - and if you do find it, it will probably be the awful Trinidadian make Peake which make you think you're staying at the end of the runway of a major airport.
We've been here for five weeks now and I have to say that bugs have NOT been a problem, no matter where we've stayed (and we don't normally use the A/C even if its available). Simply follow our advice in the Odds & Sods/Health & Safety/Insects & Nasties article.
One of the best things you can do is to call into Penny Savers on your way from the airport and buy a local electrical bug deterent. The two common makes are GoodKnight or BugMat. They cost about TT$30 (US$5). You simply put a deterent mat in the machine each evening and place it on the windward side of your bed. Set it going about an hour before you go to bed. If you're really paranoid, use two, but make sure that the breeze is flowing ACROSS the bug deterent before it passes over you. So Fan-Deterent-Sleepers.