Here's a two bucket rdwc system.. Except i used two 5 gal igloo water coolers.. It would work as well with 5 gal buckets..
This setup will circulate the water without a submersible water pump or needing air stones..
It doesn't move the water all that fast, 5-6 gal an hour... The up side to that is that the roots don't get sucked into the return line by fast moving water... Even with 1/2" lines they don't clog..
https://www.thcfarmer.com/community/threads/my-diy-medical-rdwc-rig.58171/page-2#post-1146530

I posted the above link to give a better idea of how the pumping is accomplished.
The GH pumping column sits in the standing water column that's connected directly to the reservoir.. The pumping column pumps the water from the reservoir into the grow bucket, and gravity returns it to the reservoir... The grow bucket sits a little higher than the reservoir so the reservoir can can be filled to working capacity.. the float valve in the reservoir bucket is for a auto fill back reservoir to be connected to.. if wanted..
The drip ring can be connected to the GH pumping column, under the lid.. The constant dripping of water will add enough DO to support the plant.. The splashing water from the drips will keep the outside of the basket wet, to a certain extent..
This is my idea of a bucket setup with a scrog screen support made from a tomato cage..



If you need cooling for the water an Ice Probe in the grow bucket would work.. You could get by without the temp controller by using a timer .. There's a thread on 420 that worked well with only a timer to control the temp swing..

Thanks for the info!!!! Help me understand something...why the "riser" in the reservoir side? (3rd photo)

The third pic is the grow bucket.. In the last pic, grow bucket on the left, reservoir on the right.. The 3/4 thin wall pvc water column itself is higher than the water in the reservoir and grow bucket... The water in the column is the same level as the reservoir and grow bucket... When the GH pumping column lifts the water out of the water column into the grow bucket, gravity returns it to the reservoir..
The igloos in the link give a better idea of how it's set up...
Here's a couple pics of the igloos at work with a SS 200 [185] watt draw led. frozen 2 liter water bottles twice a day kept the temps in the high 60s..18" x 24" scrog screen, 100 days from transplanted clone. 27 day veg, 6 ozs total..