I use Gitzos myself, although I know many people like Reis or Feisols.

I shoot a lot more 120 than I do 4x5 though, so I prefer a looser Gitzo ball head to keep things snappy and fast than mucking about with a precision geared head. My Gitzo Reporter held my Crown Graphic just dandy, but sadly that one vanished this summer in a cab somewhere in NYC. I replaced it with a slightly heavier Gitzo, although I'm not totally positive of the exact model. I do know it holds the 4x5 Crown just fine, and I've put a 4x5 monorail on it before without any troubles so I've had no complaints.