I would get a test ride on both the Tuono and Gen1 obviously the biggest difference is the engine layout so the way the bikes deliver their power is very different and you may instantly prefer one over the other. I had a test ride on a Tuono Factory (ohlins / carbon fibre / power chip) and had the biggest grin on my face when I got back to the showroom, If I'd had the money at the time I would have bought it there and then, brilliant handling and I loved the effortless way you could power the big V-Twin through corners. On the downside it's Italian so it's never going to be as practical, reliable, resistant to abuse / neglect or as cost effective to repair / maintain as a Fazer.
A well sorted Gen1 (replacement shock, fork overhaul, jack-up kit, lowered forks, Ivans kit, decent end can) is a very capable bike, I use mine mostly for scratching round minor A and B roads (no chicken strips on the rear) and for doing the odd day out with the Mrs on the back (she has a bad back but finds the pillion perch pretty comfy). Any time I get a whiff of upgradeitis it's pretty much instantly cured just by trying to think of what I could reasonably afford that would do anything appreciably better than the Gen1 without loosing on all round practicality. Personally I wouldn't bother with Ohlins, For the price you could fit a hardly used R6 shock, get the bike Ivanised and get the forks serviced (if your chosen bike hasn't already been sorted).
A well sorted Gen1 (replacement shock, fork overhaul, jack-up kit, lowered forks, Ivans kit, decent end can) is a very capable bike, I use mine mostly for scratching round minor A and B roads (no chicken strips on the rear) and for doing the odd day out with the Mrs on the back (she has a bad back but finds the pillion perch pretty comfy). Any time I get a whiff of upgradeitis it's pretty much instantly cured just by trying to think of what I could reasonably afford that would do anything appreciably better than the Gen1 without loosing on all round practicality. Personally I wouldn't bother with Ohlins, For the price you could fit a hardly used R6 shock, get the bike Ivanised and get the forks serviced (if your chosen bike hasn't already been sorted).