I've been getting lots of nice parts from the japan and HK based ebay shops. They've been very quick to deliver at around 5 days and they mark things as a gift on the package so you don't pay duty
I use the tamiya usa db01 hop-up list to get part numbers to search for.
http://www.tamiyausa.com/product/rcp...chassis_id=B01
So far I've put in the front one way, slipper clutch and super stock BZ 23t motor. Runs much better now
but just makes me want even more speed! I have big plans for it over the summer