This interesting sensorless BLDC driving TI technology
InstaSPIN™-BLDC, however not sure if HobbyKing has already something which implements this.
There is quite nice introduction - maybe something more than kits are commercially available?
Definitelly will put my hands on this technology after a few other projects are finished, while need drive a few BLDCs in another projects and it could be nice use cheaper BLDC motors without Hall sensors