Have you looked at the gear lists on the home page of this site? The 7-day list is probably the better one to model on. Our poster "phat" has an excellent gear list which he links to in his posts, designed for the Canadian Rockies.

In the Rockies in August you can often have nights below freezing, even snow above 9,000 feet, so I wouldn't consider the Ultralight as overkill. There have been a number of cold nights that I've really appreciated that bag! You can of course unzip it and use it as a quilt on warmer nights or, if it's really hot, sleep on top of it.

Sounds like a fun way to see the country! You may have some problems getting backcountry permits at the last minute in August in the more popular areas, so I hope you're willing to be flexible. You can always try National Forest areas instead.