I have the Invovate LM2 a/f, it is not cheap but has a lot of features in addition to just the a/f. The ability to record rpm and a/f into the data logger is quite handy.

only issue I have with it is I bought just the single O2 sensor kit thinking that I could later add the second O2 channel as it is the same unit with the plug ins for the second O2, NOT. It seems the control unit is the same but a differnt board inside that cannot be purchased seperately. So if you think that you might ever want 2 O2's, buy the 2 up front.

05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter