it does look pretty good, just never known anyone to have it before ! lol.
whatever you decide, you can still keep your EVC as thats going to be better than anything the ECU will come with.
For piggybacks most people are using the Emanage Blue, the Unichip used to be popular at one time but it seems to have lost favour now... I dont think its as flexible as the Emanage anyway.
Have you considered something more popular like the AEM stuff ? they're pretty cheap and a lot of people recommend them.
The advanatge of the piggyback though is you get to keep all the 'nicey' things from the standard ecu, like the idle control, auto choke, lambda control etc. Some aftermarket stuff can be a pain to replicate the 'nice' stuff that make the car driveable when your just cruising around.