I'm working on a 4x5 afghan box. Plan to use Harman Direct Positive Paper to eliminate negatives. Tube developers would probably be best with 4x5s as to keep the camera's dimensions down.
Used, broken bellowed, or unrepairable, crown graphics are best for this. You can find a busted 4x5 for cheap on ebay. I would just make sure it has a 4x5 back and ground glass.