Build your own with the exact features you want.

Built this 11years ago now have used it a bunch in that time. 65 gallon tank 15' single wide broadcast nozzle for yard or large areas. Narrow boom for spraying field edges driveways etc. Hand wand on a reel for most any other application rotary selector to chose which or combination of several. Broadcast nozzle has inline check valve and nozzles are check valve type as well to stop dribbling. 

I've replaced the pump/motor and just put in new nozzles in the short boom this spring.

Might give you few ideas to maximize features and capacity for your application

https://talk.newagtalk.com/forums/thread-view.asp?tid=464550&mid=3776485