jameshobiecat summed it up very well, but just to expand on that, it depends how new you want to go really. If you want another Grande Punto, the newest you'll find is a 10 plate, and the powerful engines are as James said (1.4 T-Jet 120 & 1.9 Multijet 130). Both engines are only available in the Sporting spec and are nearly all 3 door. They did a 5dr Sporting towards the end of Grande Punto production but they're rare. They also did a 1.6 Multijet (think it was 120bhp) to replace the 1.9, but again, very rare.
Punto Evo's ran on 10, 60, 11 & 61 plate, but the vast majority were 1.2s and the 1.4 77bhp. There are a few 1.4 MultiAir's, of which the most common (if you can call it that) was the non-turbo 105bhp in Dynamic and GP specs, which can be identified by a 6 speed gearbox. Again as James said, there was a MultiAir Turbo with 135bhp and there was also a 1.6 Multijet with 120bhp, available in Sporting spec. However, ALL Punto Evo Sportings are as rare as hens teeth
Finally from 12 plate onwards is the 'Punto 2012'. The 135 MultiAir Turbo and 1.6 Multijet were discontinued soon after the 2012 was released, if they were ever available in the 2012 at all. Your best bet for this age of Punto is the 1.4 MultiAir 105 (non turbo), in Easy, GBT or Sporting spec, although that too was discontinued last year. The only engine you might be able to find, which doesn't sound much but has a bit more oomph, is the TwinAir 85bhp 6 speed. It was available to start with as its own 'TwinAir' trim level (most cars around are red or lime green ex-demo's) but later got rolled out onto the regular trim levels. The TwinAir has a turbo, and despite being a 2 cylinder 0.9 with only 85bhp, it actually pulls the Punto along pretty well. I test drove one and was very pleasantly surprised - if you select Puntos with engines under 1.0 litre in AutoTrader, they'll all come up, otherwise you'll be rummaging through years and years of Mk1 & Mk2 Punto's that are listed under the same catergory (Grande's & Evo's have their own listing, as I suspect you'll know)
If it were me I'd go for a TwinAir in the latest shape Punto or a Grande Punto T-Jet (120bhp). The diesels and MultiAir Turbo's are good but very rare and whilst the 1.4 MultiAir 105 is more readily available, it's not an amazing engine compared to the others.