Gotech mfi/mini x uses the dizzy and hall sensor to tell the position the engine is at, but gotech pro is a little more advanced and needs cps input and will do batch sparks nd fuel as far as I recal. It's a fairly old system now and ages since I had any dealings with it! Someone else put there may have more info on that

In response to the op's questions, jamsport are probably best to deal with this for you as far as I understand it they supplied and fitted the system as a official dealer. (Not sure if this is still the case tho)

There are others who are willing to map it out there though. Generally it's best to find a mapper you get on with and fit the management they prefer to deal with

Power wise that depends more on your spec and the map than the management, as does what parts you need/want

Hope that helps a little