I'll be running the TrickFlow 190 power port heads so I have a few extra holes drilled for mounting brackets. I'm also running fuel injection so no mechanical fuel pump.
Looks like you are golden then. Those heads appear to match the Magnum bolt pattern on the end of the heads and are built up to match the plane.
Based on that, I would grab a Magnum TC cover, a van or Jeep PS bracket and a standard Alt/AC bracket.
Edit!!!
Just cut the AC mount section off and use the Alt mount. The big issue with the non-AC bracket is they move the idler so the truck and van PS doesn't cause the belt to rub, but the Jeep pumps are higher and don't have that issue. Both the van and truck pump that has the issue. And not sure if a Jeep pump clears the battery tray.
/Edit!!
Only other thing to be aware of is that the Magnum water pump has a threaded nose on it for the radiator fan. A Magnum fan might work, no idea, but I know they are different. Not a show stopper but something to be aware of. You could use a '91 Dakota 318 pump as they still used a bolt on fan, but you would have to find the matching pulley and the belt was narrower than the Magnum one so it might be too narrow. And no idea if the bolt pattern is the same, so an earlier fan might not bolt on either way.