I have a 7372 and R600 is there a way to set this up so that devices pick the AP providing the strongest signal?
I originally set them up with the same SSID but then all devices seemed to pickup on the 7372 instead of the R600, so right now I have two separate SSIDs
It's under your wlan's settings (Config -> Wlan -> hit edit on your wlan). You'll find a checkbox for 802.11r (FT Roaming) and one for 802.11k neighbor lists — it's best to enable both or disable both.
Note that turning on 802.11r may cause ancient clients (e.g. more than 3 year old OS'es) to refuse to connect to your network. If you have to support such clients, you may need to clone your wlan so that you have one that's 802.11k/r capable and one that is not.
EDIT, now that I have access to my ZD, I can be more explicit. Just go to Config -> Wlan, hit Edit by your wlan, and then check the two red boxed items: