Hey Sven
Installing a jet kit is really not that hard. The hardest part (on the B6 and I'm told the B12 as well) is usually removing the float bowl screws, which can be a real bugger! Make sure you've got a good screwdriver. And then reinstalling the throttle cables at the end is a real pain as well.
Anyway, based on the feedback I've seen here, the best kits to consider are either the Holeshot or Ivan's kit. Ivan's kit comes with new needles, which can open up some additional tuning options (and complexity), whereas Holeshot uses shims on the stock needles. For use with the stock airbox/filter and a slip-on can, either will work just fine. Both come with instructions and tuning suggestions.
You will find some addtional power, especially in the mid range, and warm up with the choke will be greatly reduced.
Just take your time, and follow the instructions, and you will likely be fine...(after cussing the throttle cable reinstall!!)