I've been thinking this over as well. I like heavier ambers, with that Caramel Amber being among the best. So this is something I would like to brew too.
Aging high gravity malty ales is the tradition but this is not a traditional ale. Cascade and Centennial are bright hops, they taste best young. With a good malt bill they'll balance nicely. Maybe 1.094 is a bit over the top but worth the experiment as long as temps are low and well controlled. With age (3-12 months) the character of the beer will change toward complex aged maltiness subduing the upfront hops, probably still great for Fall. I'd say aim for drinking it fresh within 1-2 months, tops. It will be something really good. And different. Have you found any other Imperial Amber recipes?
Yeah, the 70 quart coolers are the ticket. Can't beat that price either. I went with the cpvc manifold build for better drainage, and don't regret that. A HERMS/RIMS is in the future, since I like step mashes and dead-on repeatable temps. I knocked it loose only once, so revision 2.0 (side supports) needs to be implemented. Or just be more careful stirring.
I used regular window/bath silicone (DAP) since not much is exposed, it's all behind the silicone seal/stainless washer, except a narrow ooze-edge. I heard that aquarium silicone is fish (and food) safe. No algaecides, etc. Walmart may even have it.