Looking for a really nice Caribbean SPG property to take the wife and teenage daughter for 4 or 5 days this summer.

This will be my firt time using SPG points so I need some pointers on how best to make reservations using points and how to arrange upgrades. Our situation is complicated in that there are 3 so a suite or villa is almost a must have. However it looks like many book a regular room and then depend upon getting a free upgrade to a suite or villa upon arrival. This would be a little risky in that it would probably be my luck that I couldn't get upgraded and therefore 3 people would be stuck in 1 hotel type room which isn't the best arrangement for a comfortable. Given the above what would be the expert SPG users advice?

Thanks for the input.