I’ve reached another “never gonna get to these projects” moment.
4 x Dayton PM180-8 NIB - $125/pr + shipping - opened one of the four boxes to gawk and take a pic, otherwise untouched
4 x Dayton PM220-8 - 1pr NIB for $180 + shipping - 1pr lightly used for $140 + shipping
Note there is a chip out of the frame casting in the thin section around one of the screw holes (see pic) - otherwise in great shape.
These Dayton drivers are gorgeous and crazy high sensitivity, even at 8 ohms. The quad of either driver would be 100dB sensitivity per side before baffle step. The 220s will actually get down to around 50Hz, too, if you’re willing to put each one in 2+ cu ft 
Buy either quad and I’ll cover shipping in the 48 states.
Active speaker amp bundle as described below - everything NIB - $150 + shipping
2 x Meanwell SE-350-36 power supplies - 36V 350W
2 x Sure 4 x 100W amp boards AA-AB33184 using TDA7498 chips
2 x DC/DC voltage regulator (PE part# 320-617)
My plan for this was to put one each of the above in a TMWW speaker cabinet along with a MiniDSP 2x4 unit. The regulator would allow both the amp and the MiniDSP to be run from the single power supply, making for a self-contained active system, decently powered, on the relative cheap.