Beach Bum;
Northern Ambergris Caye has a few condominium projects available. Whitesands Villas, Belizean Shores, and Captain Morgan's Villas are all fine choices.
Being in the condominium business myself, please allow me to expand on some of the above-mentioned replies.
Condominiums can be great and can be a nightmare depending on a few variables. Most importantly is your relationship with the management company. I suggest that you also get a lawyer from Belize to help you with the legal work. Many condominium projects cannot offer you Fee Simple ownership (title) to your unit. There are many suitable equivalents such as a 999-year lease and Agreement of Sale which both can be stamped on the original title of the property of which your unit will sit. Another option is corporate ownership, which I personally am wary of.
Some projects need to rent out your unit to stay open as a resort/hotel. Others can afford to allow you to "lock out" your unit.
I find it best to buy into a project that has the infrastructure in place but not your particular unit. This will guarantee the amenities (pool, rest, etc..) and allow you to work with the contractor during construction to make modifications.
A few of my clients have very nice units for sale (built and to be built). They also have units, which you can use as much as you want, or if need be, lock it up. They are very flexible.
If interested please email at chris@offshorepros.com
Chris
AmbergrisCaye.com 
