My company makes, among other things, keyboards, keypads and the like. We have a switch PCB with Cherry switches in a 35 key arrangement (5 x 7) and 20 key arrangement (4 x 5). I don't recall if both have diodes on each switch or not. They do have SIP connectors with the rows, columns and have relegendable keycaps. I don't know off hand if we have a box of A - F keys in the back, but it's remotely possible. Normally we sell finished products only, and usually OEM for more well-known companies, but perhaps I can swing something for you...