Very good questions. First, for color consistentcy, you should really have two Flexi Pro 10s. Second, who is demanding the color matching? Third, Flexi allows you to print color charts. Therefore, I would suggest printing color charts on the top 4,5, or 6 media in your shop. Then, when a customer requests X color on X media, the customer can point to the color and media and say, "...that one..." Then you and the customer are assured of getting the right color.
Then, your solution is tedious, cumbersome, and pricey. The perfect solution is monitor calibration and X-Rite color calibration.