in reply to (sort of OT) cvs/vendor supplied modules/our own modifications

I'm not sure how helpful it'll be to you since you state that cvs is "the" tool, but have you tried out Arch? I found it infuriating to learn (and am still a beginner), but it seems to be better designed for the things you're describing than cvs. (It would work better if the vendor himself uses Arch, so I know this is a long shot.)
  • Comment on Re: (sort of OT) cvs/vendor supplied modules/our own modifications