The green one does look fantastic in all fairness, I particularly like the rear lights. But then the black one does appear to scrub up well, despite having a few scabs. The argument as I see it, is this; the green one is apparently more solid and so is ready to be graced with a well serviced ABF. It would make for an excellent 'sleeper', which is always cool.
The GTi on the other hand will save you all the work of the transplant of not only the engine but the running gear also, which will be time consuming, leaving you potentially carless for an extended period of time. Not an ideal situation when you're employed a significant distance from your home. You may also have to part with your beloved alloys, since, as Wayne states, the 5 stud setup is preferable.
You are more bodywork inclined, rather than mechanically.
The logical path therefore seems to be to repair the GTi.
Though I will admit I side with LowlifeDubber on the fact that I think you should keep the green one!
Good luck either way, intrigued to see which way this will go
