I have 35mm and 28mm Schnieders for just such a need. There is a Rodenstock Rogonar-S 25mm 4.0 9on that auction site right now for $29.99. Item number: 390059445637 .
I could use the Durst Board it is in shound you buy it and have a Beseler board to swap you.
I've heard of wide angle enlarging lenses, but I don't have any references for them. Schneider makes an excellent 28 mm lens, but it is really designed for half frame, and the coverage may be limited to less than full frame 35mm. Many enlargers will not allow this lens to get close enouth to the negative to focus.