First, I haven't heard that liquid in our area is priced that close to NH3 yet. Maybe it's yet to come? But, you don't have a bad idea though.

We sidedress both liquid & NH3, but not with the same bar. My suggestions would be (if I were converting a bar today)....

Use 32%...it's 3.5 lbs N/gal, vs 3# for 28%. Need to handle/flow less material.

Switch to the mini-mole knives & put the shanks back in the rows that are now skipped. Maybe skip the tractor wheel track rows. Liquid doesn't need to go as deep. But, I'm not entirely happy with wear-ability of the mini-moles either. Anyway, they will pull easier.

I'd guess you could probably lighten up the covering attachments also.

Just use a Hypro or Ace hydraulic pump...not ground drive. Use the Hiniker flow control you have now. I'm guessing it will handle liquid just fine, but of course bypass the heat exchanger...do NOT shove liquid thru the cooler.

You will probably want to add check valves in your hoses close to the outlets so you don't drip when turning on the ends and burn corn leaves.

I'm sure you realize that a 2000 gal  towable tank of liquid N is going to weigh 25-30,000#. Think about the wheels necessary to keep it on top of the ground. I think you're going to know it's back there when it's full. 

You're going to need some stout couplings between the bar & the wagon also. Don't forget to vent the wagon well also. Especially needed when bottom filling so you don't rupture the tank.

Be prepared to wash down your bar often. Liquid spatters. Or, at least it does for us and some neighbors that I observe also.

Report back on your experience if you have time.