If you want it shipped half way round the world, you probably want to get the right thing the first time. "Please offer everything" , is pretty broad.
to that end:
What ratio? With or without a Limited Slip.
What year A-body, or; What width; Flange to flange, or drum to drum
Stock spring centers or ?
5 on 4" bolt circle?
With Brakes? and Parking cables?
Just pulled core, or reconditioned, or rebuilt?
New Axle-bearings, or good used ok?
With/or without: springs, Shock mounts, and U-bolts
What about wheels?
Input yoke to fit which U-joints; 7260 or 7290?
What about a Driveshaft? to fit which trans. Now for sure we need a year & model or an exact length
8.75s have larger axle tubes, and use larger springs than the older 7.25 stuff; the U-bolts and plates of older 7.25 stuff will not fit the 8.75s. Whereas 8.25 stuff will.
73 Up A-bodies had the larger tubes, but IDK if same-width springs. Springs need matching width front mounts and shackles.
8.75s can be found with two different areas where the brake flex hose mounts to the housing; either towards the center next to where the center section is, or out closer to the springs; do you have a preference?
That's all I can think of.