Unless you have seen and like the work of the resort photographer you're better off buying your own dslr and having someone take the pictures. Make sure they have lots of practice and tell them exactly what you want. This way you pay about the same but get a free camera out of it.
I would not suggest multiple lenses or primed lenses. This adds complications and additional requirements to the less experienced. A general lens kit like an 18-105mm will work great and the guy or girl won't have to swap lenses on a sandy beach or use impressive footwork for zoom
Prime would give sharper pictures and more control over DOF but I doubt this is something most would pick up quickly. The softer effect won't be noticeable to most and could be somewhat preferred since wedding photos generally have a softer feel to them.