A 55g sump is an extremely poor footprint for efficient utilization of space, especially for a sump. That's probably why you haven't gotten any replies. I don't know of anyone who uses a 55g sump. A 40g breeder is much more efficient and common.
I have a 75 gallon tank that I was going to make a sump but went a different route. Gives you the same width as a 40 breeder just longer and taller. Pm me if interested.