Yep I've looked in details about this, I will probably go with http://www.plxdevices.com/

I'll get the basic one, I don't need a gauge, only the capacity to plus it in the computer. And what's nice is that you plug this back into your ecu and it sends to the ECU the usual narrowband your OEM sensor would see.

I will look more in details, but it's on my soon to buy list.

Etienne