Trevor,
I think all manufacturers now have websites you can visit to check out mix designs. You can find our mix suggestions at gemsealinc.net. Most producers will recommend standards that are within the ranges you listed in your message. The mix designs you mentioned are good but you may want to include applicatin rates in your specifications. Is the contractor going to apply one coat or two, or a third coat in the drive areas, and at what application rate on each of the coats? Remember, two thin coats are better than one thick coat and the more time you can give between coats the better your coating will perform. Also, you may want to ask to see some of their jobs that are a year old and actually go and check these jobs out.
