Drifting with -2deg camber I still wear the outside edge of the tyre first. Probably due to the amount of understeering I do caused by a lack of skill and a locked diff.
2-4 deg would be a suitable range in my opinion. Use the sigma or adjustable arms, adjustable strut tops and/or offset roll centre adjusters to get some camber. But giving it a go and finding out what suits is the most important.