Something like what you've linked looks good.

Alternatively, have a search over on the EEVblog forum, as I'm sure I've read some posts on there about constant current supplies (I've not been on there for a good while, so I may be getting confused with somewhere else!).
I'm sure there's plenty constant current schematics around, but when you get to that amount of current, they have to be well designed to avoid releasing magic smoke.