Club 80-90 Forums

Hi all, hope you don't mind me posting here but i'm trying to find some info. I am looking at building a trike and is based around a T25 gearbox. Not wanting to use the usual engine types like the beetle/camper or Subaru due to availability or price ect, I have seen here engines mentioned like the I4 VAG group and would like to know what would be best or would be the easiest to fit to the gearbox, there's no room restriction ect and the gearbox is marked DK. engine size isn't a problem either so i'm looking at anything from a 1.0 up to a V8. I'm after what manufacturer, models, engine size, and age will fit with minimal complication as far as fitment to the gearbox?
Thanks all
Dfbug