Multiple Wi-Fi APs: Use same or different SSID?
You can have the same SSID for multiple APs, this is how our campus network is set up, but there is a caveat that's worth knowing. When moving between APs we've noticed OS X has a tendency to "stick" to the first AP it has joined even if it's in the presence of another AP offering a stronger signal. Cycling the wi-fi can help with re-association to an AP with a stronger signal, but the fact is it doesn't always switchover automatically. Unlike Windows which allows you to tune the aggressiveness with which it searches for better APs, OS X offers no easy control over its wireless behaviour.

This may seem like a non-answer but you may find you have as many issues (albeit slightly different) with a single SSID when compared to a network with multiple SSIDs.

My advice would be to try it for yourself and see how it works for you. Be prepared for some experimentation with setting wireless power levels on your APs so you can have some overlap between APs, but not so much that OS X will doggedly stick to the first one it finds.