The advantage to printing is you don't need to bond anything. Regarding the pressure limits, only a test will truly tell. I'll print the first one in nylon, if that has problems I'll try a PC TPE. That'll have better layer adhesion and be more flexible. Probably do a combo, with PC TPE handling the inside, with a regular nylon "shell". If that doesn't work, then shapeways here we come. I'm very confident that a sintered nylon piece will be plenty strong for the base. Hopefully this weekend we'll have our answer!