lol I've just listed my DT-R field bike on ebay with the jack up kit fitted!
Unfortunately its listed in the ad so I'm unable to sell it separately.
Basically they are only shorter dog-bones and they lift the seat by maybe one or two inches when staionary.
Personally I probably wouldnt bother with them again (came with bike) as I'm going down the supermoto route so it would be daft having a jacked up back end with a lower front end.
If you want a jack-up kit get an engineer to copy the standard ones and shorten them by 10mm