Not bad starts . . . I am pondering some similar things for trough solar concentrators. Since you are starting with a fresh page (not really married to mounting them a certain way, or on an existing roof), it gives you some thinking room.
A couple of things you may wish to consider.
Weather -- Hail, wind, and snow (depending on where you are) can be part of the concern. I like your chain-gang version in that it could be conceivably rotated upside down to the protect the cells (or in my case reflectors) For serious protection they could flip right over, face down tight to the ground for the night, or bad weather.
Additional utility -- If you are putting in a serious frame that can hold a wind load, you may be able to use these as small sheds, carports, firewood storage/drying racks, dunno -- what else?
(Self) servicing -- The trough racks I am considering, I want to build to be self loading and unloading from a pick-up truck, utility cart, or trailer. But I have not thought that through, yet.