OK, I have had a little time. I think you are thinking of using two basic types of hydroponic systems. A floating system (water culture), an a dutch bucket (combination
drip system, and water culture commonly referred to as a "DWC" system). Well I still recommend starting with just a few plants if you are not familiar with growing them (not to mention growing hydroponics), you will want to have success before you expand into a larger operation. But here are a few ideas on how to build the systems.
For the dutch buckets, I would use a bucket inside a bucket. Like a 5 gallon bucket for the base, and either a 5 gallon for the top, or a 3 gallon. The top bucket would have holes drilled into the bottom for the
nutrient solution to drain down into the bottom bucket. The bottom bucket will have a through hole (or bulkhead fitting) that allows the overflow to drain down into the return line. This through hole would have a tube fitted into it on the inside of the bottom bucket, this is the height of the water level (or reserve) you want in each bucket. I attached a few pictures one that I did, I just was not using it as a dutch bucket, so I wasn't using a top bucket but it should give you an idea what I mean. Also if the top bucket wont fit snugly, you can get the lids for the 5 gallon bucket, then cut a hole in the lid to fit the smaller buckets.
The picture of the complete bucket system is a drip system, but with the addition of a top bucket (that fits inside the bottom one) it can easily be turned into a dutch bucket system. Although I would place them in rows, with each buckets return line flowing into one large PVC pipe, and the PVC pipe flowing back into the reservoir. That would be much easier than trying to flow each individual bucket back with flexible tubing.
For the pond technique, there are many ways to construct it, mostly depending on size. Large setups using concrete would probably be the most cost effective as long as it's sealed (like the lining for swimming pools, water sealant etc.), because minerals can leach out of the concrete and into the nutrient solution. But for a small scale setup like I would suggest starting with. you could use something like a small wading pool (like for little kids), these are only about 1-2 feet deep and around 8 feet wide. This can be placed into the ground to protect from high nutrient temps, but they wont be able to be placed deep enough for good Geothermal effects. Wrapping insulation around it may work as well, but it probably wont be enough for summer heat, so an alternate cooling system would probably be necessary. I have plans for such a design but cant post it here because it is in pdf. format and too large to post. I would need to e-mail it to you.
I am also attaching some pictures of another design. It's basically a upside down V shaped design, with a trough at the bottom that holds the nutrient solution, and removable side panels for the plants. The tubing inside is attached to the
pump, and the tubing would have misters/emitters that spray the roots with nutrient solution. Though this wont be a good design in case of power outages, but it might give you some ideas. The images are not complete, I have some upgrades in mind that are not in the images. But any way you look at it, I would suggest building some small systems for a few plants (whatever plants you decide on), then when you have had success and feel comfortable growing them, that's when I would suggest expanding into large systems.