If you would pm me your email and pics of the front and back, it would be a lot easier to come up with ideas using an actual visual, as opposed to something from my imagination. Aquaponics set ups could be made to look like landscaping or anything else really and camouflaging into the surroundings wouldn't be all that hard I'd imagine
The 15 x 20 could easily be maximized by going vertical. 15x20x10 would give you 3,000 sq. ft. That's a substantial amount of growing space.
We are working with a much smaller area due to the size of the yard and due to having to be able to keep it warm year round, which, since -30 being a not too uncommon occurrence here in Chiraq, can be quite a daunting task. Hence, the rocket mass heater.
Next year we plan on converting the garage into an aquaponics garden and adding a green house off the side. The goal is to continue looking for small, local, self sustaining farms, and begin trading our crops and fish for dairy, pork, chicken, and beef with a co-op of like minded people in our immediate area.
There is so fucking much we can do to make this world a better place for everyone, and it all begins with knowledge and information.