Not an easy choice at all...
For me the GTi mk6 is not in the running, I can't get involved in the timing chain issue that VW doesn't think exists?
The Ed35 looks promising, but still appears expensive compared to the best Ed30 and the cheapest Mk7 Gti.
Ed35 just doesn't seem to have the following of the Ed30/Pirelli?
If an R fits the bill, then you obviously have to consider the S3.
I've done the 4wd turbo thing.....maybe you need to tick that experience off of the list?
The good thing is, if you think and hold out a little longer, you should soon be able to find an early Mk7 close to your price point.
With the best mk 5 Gti's close to 50% of the Mk7 price, even though it's older the 5 is still a sound buy, which is probably why they the best examples are holding their money.