If your R2 partner can't make it I would love to go. My drysuit hasn't gotten much use since Alaska except for a cold day on Gore two seasons ago. I saw the post on Jacks Plastic from one of your trips on the Upper Box and it looks like fun with some serious whitewater.
FYI: I have guided for the last 6 years, 5 years commercially in CO on the Arkansas, Eagle, Cache La Poudre and Colorado, in WV on the New and Gauley and in Alaska on the Nenana. Non-commercially on the Rio Grande (but not upper box yet), Cataract, Westwater, Gore, Pumphouse, Shosone on the Colorado, South and North Fork American, North Fork Yuba and Merced in Cali, Upper Yough (MD), Ocoee (TN), Natahala (NC), Sixmile Creek (AK), Slaughter House on the Roaring Fork, Bogan Canyon on the Crystal (the first box culvert really sneaks up on you), the Arkansas from Pine Creek thru the Royal Gorge, the Poudre from Upper Mystic thru bridges except the narrows, Clear Creek from 7 pipes bridge to Idaho Springs, Gunni Gorge, and Dowd's Chute to Edwards on the Eagle. Only 6,000 miles so far, but I am working on it.