I had the DaYi back, and the widest lens that I could use was 75mm/4.5 Grandagon-N. With a 90mm or wider lens you should use a center filter to even out the exposure between the center and the edges.

I doubt there is any wider lens that covers the format and gives enough clearance to focus to infinity with the built-in back extension.

The longest lens I found that I could use without vignetting was 150mm, and be aware that you will get some vignetting if you focus too close (about 6 feet with the 150mm lens, but you should be able to get closer with a wider lens).