I'm Andy, I run Datashift IT Ltd and I make bespoke ECU's for various cars. The main theme is that they are custom made and packaged to be 100% plug and play on the car, whilst future proofing your car against further modifications.
For example, whilst I will operate the stock idle valve, use all the stock sensors, MAP, IAT, CLT, TPS and so on, there is also a 2.5bar MAP sensor onboard for if you'd like to turbo your car, and it'll also support Throttle Body conversions, and superchargers.
I've successfully made and sold in the Saxo community, and I have many satisfied testimonials now, I've mapped a turbo saxo, and a couple with Throttle Body conversions, but mainly it's the uprated camshafts that prompt people to need management.
Anyway - since you 306 GTi boys have exactly the same ECU plug as the Saxo, to make the ECU run your cars is a little rewire, the addition of a 2nd VR input circuit, and sorting out your COP arrangement.
My ECU also works out the box with the Innovate LC-1 wideband controller, but can also be calibrted to work with any other wideband.
I can add (based on interest) launch/flatshift, closed-loop boost control, that sort of stuff!
So - anyone interested? If so, I'll need a volunteer to be a donkey, preferrably in the Southampton/Hampshire area, who will have an ECU put on their car and mapped up as a test/demonstrator. Obviously you will be paid petrol, plied with tea, and bacon sandwiches and will receive an enormous discount on one of the first units.
Also, you'll be able to write back to the group whether you think my product and I are any good!!
Here are some pictures of the Saxo unit, obviously the 306 one will look very similar!!!
ECU Pic Click here
ECU Pic 2 Click here
ECU Pic 3 Click here
Kind regards
Andy