I'm sure your builder already knows this, but when puttind down wood for the subfloor, and the weather is unsure, then spreading platic over the floor is cheap and effective. You can buy it in sheets that unroll at Home Depot or Lowes that's 25 ft wide and 100 ft long. Just spread it out over the subfloor and staple it down. Then put the wall in place over top of it and just work with it in place. If you get a tear, tape it back together. You don't need it to be air tight, but the better it is, the less water that will get under it.
When the building is sealed in, you can easily cut out the plastic. What's under the sill plates will just stay there forever. This is fairly common, and I'm always coming across it in homes that I'm remodeling.
From what I've read, Advantec is good stuff. I've seen it used on quite a few commercial jobs, but I don't have any experience with it myself. For wood floors, I like 3/4 T&G plywood. I also use construction glue and screws to hold it down. I never nail a sub floor, but that's just me and probably a bit of overkill.
Eddie