May I suggest the following generation. Could be had as both Rekord an Commodore.
The following generation are cheaper too, the first Commodore/Rekord are getting quite expensive to purchase because everyone started to custombuild them in the 80´s and such, so they are getting rare.
Fun thread anyways, I have to show you my old Opel Recommodore, or "Commocord" if you want. It was a Rekord -74 they had put an Commodore -82 drivetrain in and built skirts and spoilers of sheet metal. It was a mixture between Mad Max and some odd Batmobile=)
Used it to put black marks on the pavement and scare little children
Sold it a couple of years ago, now its stripped in a garage somewhere and waiting for a rollcage and a Chevy 350 V8.