I can tell you about my experiences with the 147.
Before I launch into it I have to say that I love my 147, currently have a 1.6TS Lusso 120BHP, it's comfy, sporty and fun to drive, although I would like GTA power
1. You need to know how to look after these cars, I have found them to be very different to other makes and they can be fickle at times. Disclaimer, I didn't know how to look after mine properly until recently, all will become apparent.
2. Timing belt, Alfa say 36,000 miles between changes, originally they said 72,000 miles. In my experience 45,000-50,000 is about right. You do not need a variator at every change as long as you keep on top of the oil servicing, the water pump is generally done as a matter of course when fitting a timing belt as they have a plastic impeller that becomes brittle over time. I had mine upgraded to an aftermarket version with steel impeller.
3. Suspension arms. Every 9000 miles or the car just rattles and clonks along the road.
4. Oil changes. In my experience any car needs regular oil and filter changes, with the twinspark I would say 5000 miles or 6 months whichever comes first. They use oil as a matter of course, ~1 litre per 1000 miles on a good engine, the sump fills with junk that can kill the variator by starving it of oil, it's happened on mine. Variators are expensive, this would be my second I had one fitted when I bought the car.
5. I don't think this is a common fault but mine also needs a set of Lambdas now, ideally you should use V-Power or at the very least decent branded petrol, supermarket petrol has not treated my alfa well, even the high octane version of supermarket petrol.
6. Alfa electrics are pretty poor, I'm sure my car gets bored and just flashes up new faults for the fun of it.
7. Ah yes, my favourite. Make sure you always turn off your headlight switch before starting the car, it took me several sidelight and headlight bulbs to figure that one out.
You may think after all that I'm a real cynic when it comes to Alfa's, I'm not, as I said in the beginning you have to know how to look after one properly, if you do then the reliability will increase tenfold. I now know what to do with an Alfa and my next one will be much better treated as a result. My current one is probably beyond economic repair.
Best of luck, for your journey I would definitely choose a 1.6TS 120BHp over the diesel. As the guy said earlier, a diesel won't get nearly warm enough on that run.