Not sure my fix was what you are looking for as it required a fair pile of welding. Easy for me to do as I have a TIG welder in the workshop. You can see the results on this thread
http://www.sohc.co.uk/index.php/topic,8188.msg53869.html#msg53869 It wasn't a bought in package, all home made. Works very well though.
The reason I didn't go with the bought in kit was that I couldn't find one that retains the triangular cross bracing. They say it doesn't need it, but in reality that triangular piece adds a lot of torsional strength to stop the steering head rotating in relation to the swingarm pivot under cornering load. They say racers run these frames without the bottom tube in (to ease engine access at the track), but race tracks don't have British Gas road reapairs and general maintenance neglect mid corner. Honda didn't fit the bracing for a laugh, its there for a reason.
I would be hesitant to fit one of those kits without the bracing.