Hey there!
FIAT recommends Paraflu UP as their coolant. That's pretty expensive though. The important part is that it meets the same specifications, in that it's OAT based, the modern 'red' kind.
I bought Triple QX Red for £9 per 5 litres of ready-mixed. Paraflu UP is more like £10 per litre for concentrate, which you have to mix 50/50 with distilled water. Since my MJet takes 7.5l, it would have got really damn expensive to fill it with paraflu. I'm sure it's a slightly inferior product in terms of performance, but I don't generally push my car too hard so I'm not worried.
For engine oil, assuming you have the 90bhp petrol engine, you need Synthetic-based oils, grade SAE 5W-40 FIAT 9.55535-S2 qualification or ACEA C3 specification.
Mine's a diesel so my choice of a valvoline oil is not applicable to you. Petrols need the type mentioned above. FIAT recommends SELENIA K P.E., but there are cheaper brands available. Again, the specification is more important than the brand.
Hope that was helpful, and welcome!