I've done this section a few times but never in anything that small. The only good sized rapid at that time of year would be Lake Creek and I guess Vinegar. I've run Lake Creek twice at low water this year and did just right of the rock both times. Ruby is above Lake Creek but at low water isn't much.
For camping, the 2 Elkhorn beaches both have toilets but are on the road. There are some nice non-road options around the Elkhorn beaches and down by Spring Bar.
Here is a link to a map of that section:
Boater Guide - Vinegar Creek to Hammer Creek
Hope this helps!