The stock intake works fine. Bikes will go 38-ish just like that. I have a big-ass intake with a big-ass reed on my 104, but for an easy clean fix, they mount nicely to the stock intake.
The 15/15 also comes with the right jet in it!
I know Handybikes has the bosch ignition coil. It's for a sachs. The one for Puch works better, but is harder to get. You just have to grind a small tab off of the sachs coil and it works perfectly.
How good are you at wiring?
I'll make a wiki entry about peugeot wiring if you need a simple diagram.