You are right, terracotta pots do dry out quicker than other pots. They are also more susceptible to frost damage unless you pay the earth for a frost proof type.
My two acers have been in strong plastic pots for over 10 years now. As has already been said by Fairygirl, there are some beautiful resin pots around now that look the part until you go close up and touch them! Whatever you decide, make sure the pot is frost proof because you don't want to be heaving a large pot into a frost free place each winter!
As to siting, acers have a reputation for disliking strong winds, but mine have sat exposed on a south facing patio and not suffered at all for some reason. Better not chance it with a new specimen though, which you should keep sheltered and next to the walls of your house if possible, where they will derive extra warmth through winter, and be a bit more sheltered. My experience with them in general though is that they are tougher than folk make out.
Someone may correct me on this, but there are a lot of acers in nearby gardens, and our soil is acidic. I'm not sure if they are happy in alkaline soil? In a pot that isn't a problem as you can plant them in ericaceous compost.