And now for the choices....

Aim
Motec
Traqmate 
Video V-Box
CDS
RLC  
ChaseCam  
Pi
Stack
Racepak
Race Technology
Bosch
Rumble Strip Racing     
GPX Pro     
       

Smart Phone Based Systems

Harry's Lap Timer
Trackmaster
Torque


And some Suppliers

Austin Motorsports (Aim, Engineering, Data Analysis, Coaching)
Krause & Associates, LLC (Traqmate, AIM, RaceKeeper, VBOX, Coaching)
Apex Speed Technology (Aim, Motec, Sensors)
Veracity Racing Data (Aim, Pi, Motec, CDS, Stack, Race Technology)
Texense (sensors)
Euroamerican Engineering (Magneti Marelli)
Optimum Motorsports (Aim)
Raetech (Load Cells)
Gill Sensors (Sensors)