Childhood sweethearts Colin and Alison Jenkins have always lived in the same West Yorkshire village, but they're keen travellers and fell in love with Barbados when they first visited 13 years ago. Now they want the island to be part of their early retirement plans and are looking for a home to eventually spend six months a year in. Scarlette Douglas shows them five potentially suitable properties for their £275,000 budget on the island's lively south coast