I am not sure what exactly it is that you need for ULF film. I can share with you what I have built. (If you want I can take a couple of digital pics and post them or send them)
My sink is fairly large as I only wanted to do this once. I can fit 3 16x20 trays along the length (cross ways - sink is 32" across) and I still have the deep well at the end. My design criteria was to be able to do (4) 11x14 trays along the length and still have a 12" x 32" x 10" deep well at the end.
My sink slopes very gently from the top end to the deep well. The deep well then slopes from both sides towards the middle where I have made a fiberglass seat for placing the drain. (exact same drain as a standard kitchen sink). I wanted a deep well for washing up mostly and a place to dip my hands and rinse before going back top the dry side of the darkroom.
The "coupe to grace" is that I won on Ebay early this spring a brand new "unused" Noritsu temperature control board for less than $200. This thing is all premounted on a slab of white ABS like board, has both a cold and hot inlet cannister filters, a flow meter and of course the temperature control valve. Rather excited about getting this in place in the next couple of weeks before Xmas holidays.
I also wanted my sink to accommodate (3) 11x14 trays and the print washer at then end. (Versalab 11x14 courtesy of Bmac....thanks). I'll be placing the plumbing in place this weekend and working throughout the next week or two fine tuning all of the parts. When it is done I'll do a digital picture for you.
After blabbering away about this, I hope I did not leave the impression that the sink was a real work of art. On the contrary... anybody who can attach plywood together with glue and screws can build something like this. The fiberglassing is relatively easy once you understand what to do and what to watch out for.
Perhaps you can tell us what you are building for ULF?