the V6 gearboxes are 6 speed, TS selespeed is only for 5 speed boxes. so it'll never work.
They did make a very limited number of GTA selespeeds. My understanding is the GTA selespeed is a somewhat different system to the TS one, if memory serves it was more Ferrari derived I think - that bit could be wrong though.
If you managed to get hold of the bits from one of these, and we're talking up there with rocking horse **** and blow jobs from the pope in terms of rarity, then you could manage the conversion.