So what would be a good fuel pump to use?

12.5 340 heavily ported X heads mopar 509 hydraulic cam 273 rockers 4.56 gears 4 speed 1 3/4 headers with a weiand tunnel ram with two 600 holleys. It is in a 73 duster.

Also while we are at it how should I set up the linkage for the carbs? Open both of the primaries evenly (easy to fabricate) or get some sort of progressive linkage?

It's always cheaper and better to buy a good pump to start with instead of replacing it later if you hop the motor up more, IE stroker I would hook the linkage up one to one, direct in other words