The Fuji GF670 is a modern folder and takes terrific pictures. However, it takes 6x6 or 6x7 pictures, not 6x9. I love it but it is bulkier, and certainly quite a bit more expensive, then the 6x9 folders made back in the 30s, 40s and 50s.
The little Graflex 2x3 SLR cameras are also a great option. Since they have a focal plane shutter you can use barrel lenses. Film for it can be a bit tricky to find but if you buy in bulk from Ilford every year when they do their special film sale you can use them with no problem.
A roll film back for the Graflex would be the way to go. For me anyway.