Quinces, Hawthorns, Winter Banana Apple and
Pyrus betulifolia are good rootstocks for pears, aside from pear seedlings.
I would select rootstock varieties that are fireblight resistant such as Old Home x Farmingdale crosses, such as #33 (OHxF 33)
Here's where you can purchase them.
http://www.cumminsnursery.com/pearroot.htm