A backback sprayer would not be the way to go for me since I maintain more sq. footage in one day than you do all week walking behind a reel mower.
You have your niche and I have mine. You have a great set up with your pick up with side boards and a ramp gate. I use the same setup with a better ramp pulling a trailer (if need) with
the 62 and 52 inch machines.
I won't even take a look at a site unless its 25K sq ft or more.
Our climates are very different. It is hotter in PA some days than it is in FLA by the beach. And there are three months (dec,jan,feb) of pure hell as a bonus.