If you wire it for a 5 pin/dual ballast, you can run either box. i did this way back when on case I broke down and they only had the 5 pin in stock.
If you use an msd box at some point, just bypass the ballast and hook the 12 v side wire to the coil.
I guess I should have added the word module, 5-pin module must use the dual ballast, so yes with the dual ballast you can use either module.
If you get the 4-wire pigtal you must use a 4-pin module. If the is an upgrade to an older system then no need to change the ballast.
