if you are trying to get a similar sound to a semi-hollow Epiphone with mini-humbuckers, you are probably going to need another semi-hollow guitar...with humbuckers, yes?
If your mid-seventies Guild pickups are the HB-1 humbuckers, they will only fit in a Guild guitar, without extra routing. And I would guess they may not be the best choice if you are chasing an Epiphone mini-humbucker tone, but I really don't know. If the 70's HB-1's are what you have, they would certainly be worthy of saving, or selling, for a 70's Guild guitar. For a non-Guild there are plenty of great hums out there. I would take a look at the DiMarzio options.
Just my opinion, but I think a Guild Starfire-4/5/6 sounds great with any humbucker (unless you can find a really, really, bad sounding humbucker).