You can deal with Helix direct ;-);-)
The 6 paddle is the best choice if it also has the high pressure plate then it is rated max at 380ft/Lb and bearing in mind theres a safety margin in there it should be ok to around 400 which depending on boost levels etc could have you looking at ~450hp without issue while mapping but I suspect a few heavy launches will not do it any good.
If you get slip while on the dyno it should be quite noticable to the operator, you could then get them to dial out some torque 500rpm before the blip on the map which should stop slip starting and that will be your limit, Edd could explain it better i've only seen it done once before.