Lots to think about I'd say!!
For what my opinion is worth:
I've owned both. Id never considered an Alfa until a friend of mine decided he wanted a GTV. He needed me to test drive it as he'd lost his licence for an accumulation of points and was nearly back on the road. I drove the TS and had a ball throwing it about the Scottish country lanes...he bought the car.
About 6 months down the line he was moving to Australia and was looking rid of it, I needed a cheap car as a runabout as I was a bike guy at the time so I bought it.
My girlfriend and I one drunken night talked about driving around europe, as I was the only one with a 'half decent' car (she had a ka at the time) the twinnie was the car for the job. A few months down the line we headed to Calais (from Aberdeen) late one afternoon and before we knew it we were in France on the start of our journey.
Cut a long story short, the car was knocking on deaths door but it convinced me I loved the GTV. I had thought about working with what I had but in the end it made more sense to get a decent V6.
I have to say it was the best decision I could have made. I have done a fair bit of work to mine from I bought it and I would never get the money back if I ever decided to sell it but I do love my car (even though my brothers M3 is a lot faster!!)
My advice is test drive as many as you can and get the best sorted version you can afford. Saving a few quid at the buying stage won't necessarily be cost effective in the long run.
I would say a Q2 is pretty much a must. It will make the V6 handle as good as a twinnie (Andy may disagree but I'd happily take my chances against him if the chance ever presents itself
) As is rear powerflex. anything after that is a bonus and will save you having to have to do it yourself.....and you will want to!!
The only other thing I can say is read the guides and invest in a good one whichever you choose. I'd say Clive from CG Trading would probably be a good port of call once you've looked at a few.