Hi Joe -- --
You are absolutely correct -- any inverter of the proper size would suffice.
But -- you've asked for my reasons. Well -- here they are .....
This is the last rig I'll have before I die. I'm only installing the best of equipment.
25 years ago -- I wanted an inverter for my trailer. In researching and talking with others in various campgrounds -- they all produced an A/C hum in electronic equipment. And they were very expensive !! So -- I bought a Honeywell motor generator (I'm really dating myself now) and I still have it today -- It produces a true sine wave (no A/C hum) ...... anyone stopping by can have it !! Works great !!
Also the ProSine has a remote pannel -- this way I can start/stop as needed from the sleeper(where I installed it) and have no "standby" slight current draw. The arrangement works out quite nicely.
I believe this inverter also has about a 96% efficency ratio -- in converting 12DC to 117VAC. In comparison -- the Honeywell is about 65% efficent -- Just a little tidbit of information !!
I paid -- If I remember right 679 for it. Plus the remote pannel and 110Amp fuse -- I had the cableing and ends.
As a side note -- I've taken more "hits" on the carpet kit than the S/S fenders !! Carpet was easy to install -- Those fenders were a "pain" -- but sure work great !! :^)
Glad to see the pictures are of some help and give ideas !!