Are you talking about a Rears Pak Tank? Rears has a reputation for making some of the best equipment available.
I have a small Rears airblast with a diaphragm pump which is very well made but expensive. No problems in 7 years.
Rears and their vendors offer excellent support and may be able to help guide your decisions. I believe some other folks on this forum have Rears sprayers too.
You can turn the fan off on the Pak Blast and just use the hose connection if you choose. Its possible to alternate between the two with little effort.
I just use the AB function and adjust the pressure and turn various nozzles off and on depending on how much spray I want to put on various crops. 100 gallons/acre is probably the norm, but I get by with just 50 gallons/acre on peaches or dwarf apples which is the size of my tank. I can mix, spray an acre and clean up in less than an hour.
I am very happy with my sprayer from Iva manufacturing. I have the 25 gallon version, but they go up to 85 gallon. I’m sure they would build you a bigger one if you want.
The agitation is very good. They do not have an airblast option though.
I paid $1800 for mine. https://www.ivamfg.com/sprayers/lawn-garden-sprayer/lawn-garden-orchard-sprayers