Yes, this is post mount. Any calliper will fit but with road brifters you’ll need a road caliper, as mtb callipers are designed for v brake levers and the cable pull is different.
I’ve used Avid BB7s before and while a bit lacking for mtb, they’d be absolutely fine for road use. There is also BB5 which can be cheaper but are much more of a pain to set up. Just make sure they state road.