I talked to my Kubota dealer. He gave me some interesting insights:
1. He said my tractor already is set up with draft control and it's not available as an add-on to what I already have. He said there is a dial/knob to set the lower end of the travel and the lever sets the upper end. I have since been on my tractor and confirmed the presence of what he noted.
2. He suggested I would be able to work a 12" 2-bottom plow, but was very cautious saying I'd be taxing what my machine could do. So, not impossible, but may be on the edge of the machine's capability. When I asked about a 1-bottom, he said I'd be able to run one without a problem.
3. I'm familiar with using a walk-behind tiller and I have even used one on the land. My soil is so hard that the tiller has a hard time cutting in. Now, I realize it's apples and oranges to compare a PTO-driven tiller and a "portable" version, but I wonder if the tiller would be able to cut into my soil very well. I'm also frankly concerned about getting something with too many moving parts that are more prone to problems if I hit rocks.
4. I believe I have R1 tires. When I compare picts of R1 vs R4, it seems the tread depth is taller on the R1's and I am pretty sure that's what I have.
5. I don't live close enough to an active farm, nor I have spoken to a farmer in the area, to get local help. Besides, I'd feel like a pest for asking for help with such a small area.
Thanks. So, I'm still leaning towards a 1-bottom. I do have some chisels I'm curious about running over the land and see what they do, though I doubt they'll be nearly as effective as a 1-bottom.