Don't know your answer to a whiter rep dial, but you can build a frankin and use the gen dial. You might also be able to fit a gen dial in a rep case if you have the measurements.
Watchco is blowing out dials on ebay right now, never a better time to buy one. Here's my franken, VN case set, gen dial, hands, datewheel, Omega 565 movement and gen caseback. I also have two gen bracelets for it. The sm300 is a classic and one of my favorite watches.