I can see either a Peregrine or a Gryphon being great for this. Run some plusher volume CX tyres in either frameset and you'd be away, something like a 700 x 42 (or 29 x 1.8ish) maybe?
Mid-summer, my Peregrine sometimes runs on 700x32 slicks, and they work well too. 28's would probably lend a bit more speed as a pure road tyre (but as my Peregrine tends to nip off down green-lanes with no encouragement from me whatsoever, 32's give me (and my rims) a little more volume).
I vacillated for a while 'twixt a Gryphon and a Fargo, but in the end kept it in the family and went with a Gryphon (I wanted a little more of a MTB kinda feel, and the Gryphon seemed nearer to what I wanted). I'd like to try a Fargo tho' just to see what they are like.
*sigh*, so many bikes, such little time ...