What is the best type of beehive for tropical beekeepers(bearing in mind price, convenience of use and ease of colonisation)?

There are basically two kinds of beehives, the Dadant hive, and the top bar hive.

The Dadant hive is more efficient. You re-use the frames and comb, so the bees don't have to expend as much energy rebuilding comb. The Dadant hive also allows you to extract honey in a commercial centrifuge.

The Top Bar hive is used mainly in developing countries, due to cost and ease of manufacture. You must destroy the comb when you extract the honey.

You also need to check with your local agricultural agent. Most places in the US, it is illegal to keep bees in anything other than a Dadant hive.