The disk of a blue spot might be 9 or 10 inches but the full length including the tail is easily a foot. If our little LFS in Prince George can bring in a blue spot you shouldnt have any problem getting one where you are. However how are you certain that you will receive a 'small' one? These are never stocked and need to be specially ordered so there wont be much to choose from. The one we had in town was a full foot long. Cortez are regarded by most as a more suitable ray for home aquaria.
I did a search for 'blue spot ray' on
www.reefcentral.com in the Fish Only and Aggressive Tanks section. Only 3 pages of results came up but maybe there is something in there that will aid you:
http://reefcentral.com/forums/search...=1547138&pp=25