Thanks. Actually trying some of this stuff helps with figuring out which software does which range of things. I installed space desk, set up my iPad as an additional monitor and dragged the PFD over to that. I can see the point about that being a bit small but I’ll probably give it a shot with Air Manager before I splurge for a pair of touch screens. I’ve got the Arduino and the DIY knobster inbound currently. 
Hopefully this thread helps someone else in the future, or maybe the older threads were useful and I was being thick 