Styling wise I'm quite fond of both the Punto Sporting and the Corsa SRI (just looked at pics, but quite like the normal styling too) and in terms of build quality they're both more or less the same too. So really it comes down to engine and cost.
If the SRI comes with the lovely piano black interior from the VXR then that's good news, though the Punto's is also a nice place to be. I'd say the 1.9 of the Punto is already a better engine to start with, and when you bring mapping into question you're onto a winner.
I own a 13 year old Panda so I think you can assume I'm treating both badges equally.