I'm afraid that I stopped reading it after it got to 2 pages!
I personally feel that there is a very real place for 'cobbling' as you call it. I would prefer to call it a 'custom-built system' or a 'bespoke system'

You would have to rank my own system that I use for my commercial contracts as a 'bespoke system'. It consists of a custom built tank, custom built drip tray, custom built tank restraint bars, a Flojet pump and strainer, a switch and wire, 1/2" hose, splitter and two hose reel connections. Very simple and put together by myself (the tank, drip tray and tank restraints were built by professionals though). Total cost = about £570.