I got my jets from jetsrus. The aftermarket main jets work well, but not the idle jets (would not run, if look close, orifice is not the same shape). After buying one aftermarket idle jet, which gave me a lot of trouble, I bought the OEM Keihin and they worked well. Don't expect jetsrus to accept any returns.
I have Tecnigas Next-R pipe on my 2005 People 50 2T, pod air filter, Malossi variator, and re-jetted carb 105 main, 45 idle. My elevation approx 1000' and hot, so Denver will take smaller jets, not that much IMO. Mine may be a little rich, now that it's summer hot. I would be rather be too rich, I run my WOT for long stretches. Runs like a champ, a very nice riding scooter, I love it.