I haven't done a G60 conversion but the only real hurdles will be wiring. It's best to convert the mk1 to CE2, just soldering and testing with a multimeter to make sure it's wired up properly. You can piggyback the rado fusebox although it's not really the best option.
The downpipe and engine mounts will be fairly straight forward. Obviously use all of the G60 brake setup. Can't see any major issues with rad etc either, may need to fab some brackets up but space shouldn't be an issue.