Figure out the total acres needing spraying. Since only spraying rows, I would assume maybe 10 acres total? And is this a one time use or do you plan future use? So at 20 gal/acre, you need 200 gallons. So I would want one at least 50 gallons. Budget is a factor. A 3 point hitch version with a PTO roller pump will cost easily $1000. That's a lot for one use. So that leaves a 12 V pump, which would work fine. But most atv units are 25 gallons, so too small for efficiency, but doable with multiple refills if you don't mind that. A trailer type is also costly and most entry level ones have cheesy wheels and tires for a rough pasture, whereas a well built one for farm use will also be well over a grand.
I built a sprayer that fits in the back of my truck using a $50 tote (275 gal) and a good 12 V pump powered with a standard battery like for a trolling motor. Plumbing parts were all common hardware store stuff. You could buy a boom type sprayer assembly from Northern, modify it slightly, and divide it so it would spray 2 or 3 rows in one pass. You could spray all 275 gallons in an hour easily from the comfort of your truck. Cost would be less than $500. I just sprayed over 500 gallons this way over 30 acres of food plots and trails scattered over a thousand acre tract, in one afternoon.
I also have a 25 gal atv sprayer, but it's a pain to refill it 10 times. But if I used it, I would pre mix 200 gallons in a tote in the back of a truck, and have someone follow me to keep me refilled with a simple pump. That would be the cheapest, and you could easily resell the sprayer when you're done.