I would always take the high concentration repellent (nearly 100% DEET) to keep weight to a minimum. Just be careful how you carry it -- it removed some paint from my camera once because I handled the camera right after applying the stuff. I now carry the container inside ziploc bags, and wash the palms of my hands after using it.
My defense against mossies is a head net, long pants, and a long sleeve shirt (sometimes with a spritz of deet to the shirt if they can bite through). I apply deet only as lightly as possible and as necessary.
If you are prepared for them, mosquitoes won't bother your trip.
