Not sure what your budget is, but I run a pair of used MP40s in my 60g cube. They're not cheap, but they're not terrible when they're used. MP10s will get you there too, but you have to run them harder than the 40s.
Jebao powerheads get solid reviews for the price. I've never used them, but I'd definitely consider buying them if I couldn't swing some used Vortechs.