Suggestions for Running Shoe Stores

I am beginning to think the running sneakers I have been using are not the right fit for me and am hoping to find a running store in Mercer County or not more than 30 minutes from Hamilton/Trenton that will do a thorough gait analysis and possibly a return policy on sneakers even if they have been worn because afterall, how can you really tell if it is the right fit unless you really use them for a run.

Any suggestions would be greatly appreciated!
Thanks!