I'm using a Minolta Rokkor 50 2.8 on my Federal enlarger for 35mm, and a Wollensak Raptor 90 4.5 for 6x6 and 6x9. Great glass, small investment. The Raptor stopped down is very sharp even though it's 4 element. A Nikkor 50 2.8 would also work great for 35mm.Nothing wrong w/ Paul's 50 4.5 lens either, just a little harder to focus than a 2.8 lens.
Made my own lens boards because they're very easy to make. They're just flat squares, so whatever you have around the house (thick plastic, thin wood, whatever) works fine for a lens board, and the enlargers are fully capable of 16x20 prints from 35mm to 6x9 (mine are Federal enlarger models 311 and 312). Your 269 is almost exactly like my two I think, and should be capable of 35mm to 6x9 negs.