I've used the aforementioned Aluma Hyde II from Brownells-works very well and can be touched up quite easily. I found out quite by accident that you can remove the paint by simply spraying Birchwood Casey's Gunscrubber on a rag or paper towels and rubbing the painted scope--it will remove the paint completely.
Try the Alumahyde, I think you'll like it. It's cheap enough and like I said, quite easy to remove if you don't like the finish.
Hope it helps.
