I just installed new Tecnigas Next-R on People 50 2T. This pipe fits People 50 2T, Super 9, Super 8, and some others. I have older Tecnigas pipe on 2003 Super 9 LC and it's loud, especially with pod air filter. However, with stock airbox, the new pipe was surprisingly quiet, even with pod air filter it was fairly quiet IMO. I now think my old Tecnigas pipe needs to have the muffler repacked.
For city traffic top speed 30mph or so, I am not sure you would be happy with Tecnigas Next-R pipe. Low end, my 05 People 50 2T actually performs really well with stock pipe. I was lucky to find an older one that has very few restrictions like the new ones. I think if you get a quiet aftermarket muffler with restrictions you can easily remove, you will be very happy. I did notice the pipe you last linked to may have an internal restriction that would be hard to remove, I would be leery of that one.
And congrats on your new Super 8 50 2T. I have 05 People 50 2T and 03 Super 9 LC. I would love to have Super 8 50 2T, very cool scooter IMO.
Cheers