Anything that is quince compatible will work. There’s a thread here listing many varieties.
Quince as a pear rootstock is highly under-appreciated, it is by far the most dwarfing and the most precocious. The compatibility issue is easily solved by an interstem – if you are not sure if some variety is compatible just add an interstem. The only downside is suckering, and in particular those suckers can get blight strikes which can kill the tree. That said even in bad blight years that never happened to me. Also at some point it gets too cold, I think zone 5 and up is OK.