Looks like a pretty good deal. Something else to think about though. I just finished a plumbing job on a 90 gallon and was originally going to use a 20L tank as a sump/fuge. I got as far as gluing the baffles in place and decided that I would really like to have a bigger fuge than what I could squeeze out of this set-up. The 20L is actually the same dimensions as the sump you're looking at except that the 20L is 6" longer. You're not going to have much of a fuge with this thing.
What I finally ended up doing was using an acrylic sump with the same dimensions as a 20H. I picked up a cheap 10 gallon aquarium to use as a fuge and took both tanks to the glass shop and had them drilled for 1" bulkheads on the ends. These two tanks fit perfectly under the 90 gallon with about 2" between them and I just connected the two together with a short piece of 1" PVC
. This gives you really effective space utilization in the stand and a lot bigger fuge.
If you don't feel much like a do it yourself project then what you're looking at looks ok, but I think it might be smaller than the picture makes it look.