There are many Rapid Prototyping technologies that you could consider, not just SLA. I would recommend that you look at SLS - Selective Laser Sintering - which I think uses nylon, and produces parts that are as accurate as an SLA, but extremely tough. Very good for snap fits, and parts that need to flex a little to assemble. I could recommend an outfit in Australia called Solid Concepts that I've been using, but I'm not sure that I'm allowed to.