I use the Nikor tank usually, but if it's just a few sheets, I'll use trays, and I have about five hangers for this format, so when I'm exposing for the developer I'm using in my deep tank or if I've got enough film to merit mixing up a 1 liter tank of another developer, I'll use tanks and hangers.
I've also used the rack from a Yankee tank, but in larger deep tanks. If you try this, be sure the sheets are pushed all the way into the rack, so they don't fall out.
I'd love to have a deep tank line. It just seems like sheet films and deep tanks go together like...peas and carrots. Which tanks do you have David? I'd like to get the stainless steel tanks but, they do not seem to come up for sale often....are there others that you can recommend. If I had 'em, I'd use them for 4x5 (mostly) and 5x7 as well.
I have mostly 5x7" 5-quart hard rubber tanks, and then I've got some Kodak 4-quart hard rubber tanks, one plastic one of recent vintage--Cesco or some such from B&H--and one 1 liter 4x5" stainless steel tank that I use mostly for monobath processing.
The old hard rubber tanks are usually cheap, but heavy, so it's best to find ones that don't have to be shipped too far. They usually need to be cleaned fairly thoroughly, and some may have cracks. They're plentiful enough that you're better off just buying more of them, rather than fixing them, and using the cracked ones for washing film or as dry tanks for holding hangers as you load them and for storing extra hangers.
I saw one of these Nikkor sheet film tanks at the Keeble and Shuchat museum. I talked one of the clerks into letting me fondle it for a few minutes. It is a thing of beauty but, alas, they are hard to come by and too expensive these days.