Hubs are the same on the petrols AFAIK, only the ST170 hubs are different.

I would imagine that you can keep the same ECU, if you're just swapping engine and no ancilliaries over it shouldn't be too difficult a job, did one myself on a Renault Megane in 1/2 a day, not bad considering I'd never touched a french car before.

Look into it, but might be better trying to get the engine from an Auto... they won't have been revved hard or redlined at all, so might be in better nick.