I was going to buy a full car as a donor and swap all the bits I needed. The old engine is a 1.8d with about as much pull as a relient robin. I was looking on the lines of the cvh as I grew up with these engines. I wouldn't waste my time on those old rattler engines due to so many weak points on them.
I expected some chopping on the dash and some of the wiring loom when it comes to the rear lights. All that part is easy enough as most of it is plug and play anyways.
I did see somewhere a couple of years ago a mk4 with a mk5 dash in and wondered if it was someone on here that did the conversion.