I run a similar operation that I started 6 months ago. I use the dried manure to make byproducts for mushroom growing. The manure makes me FAR more than the rabbits do... and I breed as aggressively as possible to maximize rabbit profits. I don't use a "laboratory setup" as you suggest though. On a large scale it just isn't financially sound. Even if your chain of stores is funding the business they will need to be able to make more off the manure than the cost of building and operating the business. You can get clean dry manure with a normal rabbitry setup that uses manure runoff slides to separate out the urine, then further dry the manure outside in large flat bins. I currently produce, dry, grind, and sell about 50 lbs of manure per day with 40 breeding does. Just make sure you hire someone to manage it that knows how to farm rabbits and isn't afraid of working with manure daily.