Hi again RandyP,
I did some checking for you regarding some of the recommendations I made above, and the outcome is quite favorable. It appears that the Sailworks Retro 6.0 has an open top, thereby offering an adjustable top configuration. Also, the 6.0 has a 458cm luff, meaning the extension out the top is only 2cm, which is quite viable without really changing the intended character of the sail. Furthermore, the 460cm Joystick mast has been identified as a alternate mast choice. On top of that, the 460cm Joystick is shown as the ideal mast for the 7.5, or an alternate mast for the 8.0 Retros.
With respect to Chinook booms, the aluminum ones come in different length ranges for the same price, so getting the optimum boom sizing is a relative no brainer.
In the long run you should be able to virtually retain the same price overall at your retailer with the larger mast and the appropriate length Chinook boom, especially since you aren't going with any different brand mix than featured.
I guess the only real bump in the road is whether you invest the extra in the 7.5 or 8.0 Retro sail. I'd invest the extra ($400-475 USD) for the bigger sail too, and you'll be comfortably styling for next season.