I suppose you know about the trick of reversing emitter arrows on NPN transistors, thus reversing PN junctions, turning them into PNP? (Apply similar action to Nmos & Pmos.)
And change the sign on supply rails?
As for 0V ground, designate it as a centerline between the supply rails, or as 1/2 supply voltage, depending on your setup.
The long-tail pair (differential detector) has the tail resistor (or tail component, or current source) near the positive supply.
Likewise note that a P-type long-tail pair has its emitters or sources (of current not electrons) facing the positive supply.