Lapla is the flat lensboard, and best for 75 or 80 mm lenses; Setopla is the recessed lensboard, and best for 50mm. You can use the Setlopla for the 75/80 mm but will be limited on the smallest print size. The Setopla cannot be reversed. Both were available in 25mm and 39mm threaded versions, and I found my Lapla 39mm lensboard on ebay.

I recommend a heat absorbing glass in the filter drawer, just on theoretical reasons--that would not have to be Durst, just one the right size.