Not exactly citrus, but I would go for the typical rootstock hybrids...
Other interesting citruses and pseudocitruses:
Citrus aurantium
Poncirus trifoliata
some Unshiu varieties (but they do well in warmer climates with not very cold and long winters)
Citrange (C-32, C-35, Troyer,
Carizzo...)
Citrumelo Swingle
Citrangequat Thomasville
and maybe some hybrids.
Not many of them produce edible or tasty fruit.
