It had to be "stylish" (whatever that is

Anyway it's about the same size and weight as a Bongo, but a 3.0litre TD with a 6 speed auto box with factory fit cruise control, electric everything inc. TV/DVD built in to both dash and seat backs.
We took it down to Oxford yesterday (to show new babe to G/Granny) a nice easy trip mostly on dual carriageway/motorway used CC for about half the round trip and cruised most of the way at 70mph with quite few quick "squirts" past dawdlers and the like and brisk pull aways from the numerous roundabouts - no real attempt at "economy" driving.
We reset the trip computer for the return journey and it settled down to an average of 37mpg

So the questions are.......................
Can I fit a BMW X5 engine and gearbox to the Bongo? and if so what would the payback period be?

Would the 255/50-19 front and 285/45-19 rear tyres fit in Bongo wheel arches?

200+bhp, shed loads of torque and a 6 speed auto...............jibber jibber.