Zeitronix looks to be a decent feature rich unit.
We used a PLX R500 in the USTCC WRX and found it to work well.
I have used plenty of the Innovate units (LM1, LC1 etc etc) all of which I have found to work well.
Our dyno has a LM1 built in which I will piggy back with a Motec PLM when the occasion demands it.
Mike