What is the beach like? Soft sand or rocky? The Hobie 18 is a great boat for that but if you want "better performance" well, that means lighter, so no matter what you get, the hulls won't be as tough as the Hobie 18 or 16.

This only matters if there are rocks around. You will want beach wheels anyway, just to move it about.

What's your budget? Do you want new or used?

There is a classified section right here but most of the boats are pretty far from Mexico. How far south of San Diego are you and how far do you want to drive to pick it up?