In regards to handling the Twinspark engines are alot lighter so this does give better handling over the V6, but the V6 lump kicks out 220BHP and can propel you from 0-60MPH in around 6 and a half seconds and take you upto 150MPH,
The Spider might be a good choice in its V6 guise, but I wouldn't recommend it with the 2 Litre TS variant as they are supposedly a bit sluggish. (0-60MPH in 9.5 seconds etc)
The 2 Litre TS engine is pretty good though in the GTV, 0-60MPH in 8.4 and top speed of 137MPH, not bad at all really.
The prices for the V6's have dropped considerably, what would be a £5000 car a year ago can now be had for £3000-£4000.
If you check out eBay there are alot of V6's on there for sale, probably due to the tax and fuel price hikes.
Then again, a decent 2.0TS can be had for around £2000 nowadays.
There is nothing quite like the noise of an Alfa engine revving high, and although the TS engines do sound good the V6 roars and sounds stunning,
Good luck with your search mate!