Cotton real style flexible mounts like on the cossie are a good simple option for any after market fitment, you just need a bracket coming out of the engine and a bracket coming out of the car a couple of inches below it, drill a hole in each and you have a mount, so its just a case of knocking up the brackets to fit each half, which you can either base on the existing ones or do out of 4mm plate or whatever.

Its very application dependant though of course and ive seen it done lots of different ways.