I'd hazard a guess and say the power output (at the minute) could be around the 85-87bhp mark - taking natural wear and tear on the engine into account.
Not sure on the 2.0 injectors. I would've thought they'd just flood the engine - may be wrong though.
Bill Blydenstein reckons on getting a 20% increase in power from the SE head - that'd depend on whether the work done on your spare head was roughly the same as what Blydenstein usually does.
You never know, you might come close to GSi power with the head/cam on there