Question in my mind is what would you do after you get your PPL.
If you plan on extended trips with family, the PA28, especcially the 180 hp version, is the plane to go for and to fly. Equally, if you are looking to possibly buy one later.
The Tecnam is a great little airplane, a bit short on payload, otherwise a nice fun plane for 2 people. Friend of mine owns one and has done quite a few nice trips with it around Europe. As for quality... Tecnam is one of the very few successful airplane manufacturers at this time and this would not really happen if their quality was lacking. Instead I rate them as one of the innovative and pretty sharp players in the market today.
If you plan on renting, you will find PA28's everywhere whereas you may struggle to find Tecnams.
In the end however, I can't agree enough with the statement that the quality of the instructor and school are much more important than with what you finish your PPL with. In any event, the PPL is a license to learn on your own and probably you will find in the future that you will fly other airplanes than the ones you trained on. So find the best over all package and go for it.