You should probably have a jeep technical manual.
The timing cover IS the housing for the oil pump.
Both gears (one gear sits on the shaft secured in the cover AND the other gear is affixed to the shaft which will stick THROUGH the cover and engage the distributor) are housed in the oil pump "housing" which is actually part of the timing cover.
When you get an oil pump for an AMC V8, you are just getting both gears (one mounted to a shaft, and another which you will put on the shaft already in the timing cover), a gasket, long spring, and a funny metal "piston" which is part of the oil pump pressure relief.
Did someone actually see your timing cover and say you needed a new one?
You may not need a new timing cover at all. However, there are several reasons you may need to get a new timing cover: if the timing chain was very loose, it might have "slapped" the inside walls of the cover, water passages could be severely pitted or completely corroded through, oil pump housing could be severely worn leaving a too much clearance between the gears and the housing walls, etc etc.
When you have your timing cover and are ready to work with the oil pump parts, you need to be conscious of lots of details. There are oil pump modifications that can be done to the oil pump housing. Check for various threads on this subject. I'll attach diagrams if you cant find other threads. You also should check clearances between the gears and housing. Also it would be a good idea to get your hands on Plasti-gage and check the pump gears for clearance once the cover plate is bolted on and torqued correctly WITH a gasket. (BTW: do not use gasket sealer on the oil pump end cover plate) If the end clearance between the gears and pump cover plate is wrong, that is a fairly easy fix. You can buy a part to accomplish this, or you can actually fix the problem yourself.
If I havent mentioned this yet, get the jeep technical service manual or a really good manual of another brand. If its a good one, it will go into detail about the oil pump.
Trust me, buy a good manual. If you can actually find a "jeep technical service manual", buy it.
EDIT: I guess what I'm saying is .... take your time with the oil pump. Its a very small box of parts and the initial thought is, "I'll bolt it together in 5 minutes".. DONT DO THAT. You want to have good oil pressure in your new engine. Ensure this by spending time getting to know how this important part works, and actually go through the appropriate methods of checking it...