Blimey - you ARE an enthusiast - ignore those who say that after a cambelt failure the bottom end of the engine will fail a few k later. The belt went on the 147 at 46k miles - now up to 100k and still runs sweetly.
That's just on the 2.0 litre isn't it?
Daytona, things to check at that age are squeaking from suspension this means the wishbones need rebushing or replacing.
Knocking from front wheel's on both my 147s it has been nearside predominantly this is the Anti Roll Bar bushes and/or droplinks, again can be rebushed by a knowledgable indie or just replace, if you go for replacement I'd replace it with the GTA ARB it's a very good upgrade to a 1.6 147... in fact I did
Gearstick, check to make sure it selects smoothly, also ensure it self centre's properly and check for signs of crunching going into gears. If it does this run away unless they are willing to drop £500-£1000 off the price so you can get the gearbox refurbed/replaced.
Repetitive Bulb warning alerts are generally from poor quality bulbs that don't fit properly.
Cars with XENON headlights need to go back to Dealer for bulbs to be changed, this includes sidelights, factor about £40 for a sidelight on a XENON equipped car.
Oh go for a Lusso spec car too, it's better all round for toys and comfort. Make sure the Radio code is with the documents.
Um... that's about it that I can think of that's specific to the 147, put the general stuff for Alfa's on top of that like Oil and Service History and whatnot and good luck