I'm the opposite. If your field isn't just full of rock, I would buy the plow with the coulters every time. Coulters are invaluable for keeping trash from collecting on your plow. Believe me, when u have to jump down and clean the trash out from the hook on your plow for the 20th time in 2 hours, you will be glad you figured out how to use and adjust your coulters.
Also, draft control is your friend. If you only have position control, then a trip plow might be the way go. (I don't even know how to plow without draft control, it would be awful) Position control is great for blading, scraping ,brush hogging, etc.....but for anything like plowing or disking, draft control is your answer. I turn out an occasional rock that is softball size or bigger in one of my fields, and have two really rocky spots, and my family has been using the same 2 bottom plow since we bought a tractor in 1952. The awesome part of DC is that it floats the plow in the ground and adjusts its depth automatically depending on what you encounter. If I hit a big rock, the plow jumps out of the ground, or at least floats right over it.
Trash is my enemy with plowing. If you cut your fields first, give them some time to rot the trash down before you start plowing (usually 2-3 wks) I can flip over sod with foot tall grass or higher all day long without stopping, but give me a bunch of weed trash in a field (johnson grass residue is the worst) and it will take me twice as long to get the field done.
Good luck!