Might have to find a set of quads here or on ebay. Vintage ones show up on ebay fairly often. I bought a pair (2) for $200 last year and saw quads go for about $400 sometimes just under if your lucky. I don't think there are any current production cabs that use those. WGS makes a 65 speaker too. If your wanting to find a company that makes a cab with those already in them maybe find one that is using WGS G12-65's in their cabs. Or Marshall cabs from the early 80's often had 65's factory installed.
WGS link https://wgs4.com/content/et65