I would look at it this way bud. You are basically asking us whether you should buy the car you want or buy the car you can get... I think the answer is obvious as to what you should do.
I have a mk6 GTI and I toyed with the idea of going all out with a turbo upgrade but tbh it is alot of work. If you are ever going to want over the 300bhp mark I would get the ed30...
I've been in a 360hp Ed 30 and it handles the power crap in 1st 2nd and 3rd mostly so that also put me off. That having been said though the DSG goes along way in controlling the additional power.
After my experiences I'd say an Edition 30 taken to 300hp with DSG is more than enough. Beautiful car... all the power you could want and use and a friendly power managing gearbox (just upgrade the brakes

)