Old style LA water pump or new style water pump With A/C

So there is a lot of information all over about the different style water pumps that came on the LA blocks. From what I've gathered if you have a pre 1970 LA block the timing cover is different (either a bolt on tab or cast into timing cover on passenger side) and the water pump is different (inlet is on the driver side).
It seems easy enough to find the regular type of water pump for pre 1970 but finding an A/C style pump is more difficult and when found the price is just about as heavy as the fact that it is cast iron. But even if we find or have the correct pump we may still need to locate the proper timing cover (cast timing marks or a bolt on tab). As well the radiator needs to match all of the above, with the outlet spout on the passenger side, or vice versa depending on what side of 1970 you are on.

First off I suppose all this only matters if you are running A/C on your car. Was the timing mark moved because the radiator was changed or was the A/C located differently, making it more difficult to read the timing marks. Is anyone using a later model timing cover with the older style water pump and radiator, if so how difficult is it to read the timing, easy hard, impossible? Also is anyone using a non A/C pump with a proper A/C pulley. Or better question is there a way to use a non A/C pump on an A/C car successfully?
Which brings me to another question regarding the flow of the A/C pump. I was visiting a local re-core shop and the guy said you can get new lines that are "dimpled" which slows the flow to allow the fluid to remain in the lines longer to further help with cooling, which kind of contradicts having a high volume/flow water pump. But I also read that the A/C pump has fewer blades which cause slower flow rates but at the same time have a smaller pulley which increases the speed of the pump to increase flow. (This is where my primitive brain starts to get dizzy) So my left side of my brain says to the right side, we will need a slower rate pump, but a faster rate pulley, with a slower flowing radiator if ya wanna run A/C? I need an aspirin.

So for all of us out there that are adding an aftermarket or sourcing an original A/C in to a pre 1970 car but no longer have the original engine or radiator (which is probably very common) or perhaps one or the other. What would be the least expensive way to go. Assuming they are not looking for the OEM look, just something to keep cool while driving a lone desert road at 100F.
My personal situation I have a radiator from 1968. 5 timing covers from 1970 and up and one timing cover from a 1965 273 with a missing timing tab. I will need a new water pump also. That is why I am curious if we can run a non A/C pump on a car with A/C somehow.
Or would it be best budget wise just to go with everything 1970+ rad, pump, pulley (was there a difference in the A/C pulleys pre 1970), and timing cover.
Edit: When do we use a pump with 2 port holes on the top as opposed to the pumps that have one hole on top?