Sounds like you have a wonderful child, and I'm very familiar with the difficulty of deciding about schooling while the kids are so young. My kids, both under six, haven't been tested, and everything I've read is that unless there is a need to test (possibility of disability or behavior problem), or a use for the test (such qualification for a specific program), testing is not necessary or indeed useful.
For your immediate schooling question, definitely don't assume that the district with gifted services is better. Our school has no gifted services, and I couldn't imagine a better fit for our ages. Do pick the better school, but base it on teacher quality, turnover, resources, and part of the discussion can include advanced kids -- but that's not the whole story of any school.
