I can’t help with mounting location, but here are some parts I’m using on my Jeep that I’m super happy with:
Universal quick disconnect (very high quality):
Coupler Body, Brass, MNPT, 1/4 In. Pipe
www.grainger.com
Cover that happens to fit quick disconnect:
Dixon Valve K4DC Nitrile ISO-A Interchange Hydraulic Fitting, Dust Cap, 1/2" Coupling, Black
https://www.amazon.com/dp/B00DE8V4G4/ref=cm_sw_r_cp_api_i_lYPRCbT3QQMR2
Bulkhead fitting for quick disconnect, can probably source many places:
Air Quick Coupler Bulkhead Fitting (AQC-2)
absolute-wits-end.com
Cool array of misc brackets (and more) if you decide not to punch a hole in your bumper:
OBA Accessories from Wits' End
absolute-wits-end.com
For mounting my quick connects, I just cut a simple, square bracket from aluminum stock, drilled it out to accommodate the bulkhead fitting I linked, them sandwiches the bracket between the frame and bumper (in each rear wheel well). The bracket is held in by the bolts that attach the bumper to the frame. Might be Jeep specific.