The GTA Selespeed is different to the Twin Spark one and is similar to that of the Maserati Cambiocorsa system. The gearbox is actually the same as the manual, which means it can - in theory - be changed from a hydraulically oriented rod to a fleshy human foot, but at some cost and complexity.
The thing I’m concerned with about Sele GTAs is parts and finding people to fix it - they sold just 1 or 3 officially when the car was brand new, and some more much later (2006) when a boat load of RHDs heading for Asia became a bit burny and had to come back to the UK. The issue is parts and knowledge base…