I have been dealing with Malossi USA On Line for several years, and from what I have heard they are closing shop! I'll do some looking around for a good kit, and price for you. Right off the top of my head I would be looking at the Malossi cast iron (durability), Polini corsa (good power at a usable rpm range), or the Arisol aluminum (best price for an aluminum jug kit. Moped hospital may be a good place to look at the arisol, but I think they are fairly high priced. Scooter works is a good resource, and scootertronics has the worst rep, but they do have good prices if you want to wait, and wait, and wait some more. There are several pipes that can be used, and that choice is really up to what you want the scoot to sound like, Everything from an open bullet type to expansion chamber designs are easy to find, and fairly well priced. Do a little searching, but try to stay w/ the proven brands, and don't be tempted by the cheap stuff.