Ditto on the recommendation to do Mariscal Canyon. Considering the cost of hiring a shuttle, you definitely need to figure out a way to self-shuttle this trip. 4WD is definitely necessary for this trip, especially for Talley Road. If you're not up for the Cross Canyon Trail hike, try using mountain bikes to shuttle back from Solis to Talley. It's 18 miles, but not too difficult. We had no problem floating the canyon and biking back to Talley in a single day (late October).
Here is my trip report on this float, complete with a Youtube video I put together.
http://www.bigbendchat.com/portal/forum/your-trip-reports/mariscal-canyon-1015-16/msg97817/#msg97817Enjoy!