I still think it's a shame that Kevin Vernon stopped offering his Ecotec engine conversion. It used a GM/Opel Z18XER engine as fitted to the Astra and Zafira, but with an MBE ECU.
The engine is a peach, very light and compact, and features variable valve timing and variable-length inlet tract. The original spec gives 140bhp from 1800cc, but the MBE ECU takes that to around 165bhp with no other mods. Torque is around 150ft-lb
The really neat thing is that with these engines the catalytic converter is integrated into the exhaust manifold, so it heats up very quickly and enables a really neat installation into the Morgan engine bay - the only engine mods required are a different bracket for the accessory belt tensioner and a metal cover for the electrics above the injectors.
My car was one of the five or so that Kevin did, and over the last 10 years and 40k miles I've been delighted with it.