My dad would process 300 lbs of bellies into one 55 gallon barrel on a dolly, stacking them one on top of another, rotating randomly, then fill the bucket with brine, then weigh them down with a 5 gallon collapsible plastic jug filled with water, shove them into the brine cooler, and recording the barrel no. on a huge chart with the date put down and let them sit and cure for 21 - 30 days. There is no special handling to the bellies, no need to keep them separated, etc. Where they touch they stay pink vs. a pale gray, it's part of the myoglobin process and does not affect the curing whatsoever. You may not need as many containers as you think. He would do hams the same way after pumping them, 18 to a barrel. I put down thousands and thousands of lbs. of hams, bellies, chickens, turkeys, tongues, roast beefs and briskets for corned beef and pastrami, and so on.