You can use any sensor just need to calibrate the dash. I have 150 PSI SS sensors for 100 each that can be used for alky, fuel, oil, etc.
And these sensors you should already have with the XFI. As the logger will read any sensor the XFI already reads through the CAN bus.
The neat thing is the wideband display.. and the alarms you can setup with it.
The only downside is the logging software wont work with Vista. The Dash works with Vista, the datalogging software doesnt.. yet. Does work with XP.
I love mine.. beats buying 10 different guages and cluttering up the cockpit.