I have received the message below from Mr. Cobb - please respond directly to him if you are interested in accompanying him on this trip or have suggestions for him:
Message from the website contact page - From: Johnathan Cobb (jgema2010@gmail.com)
Hi there,
I'm trying to plan a big adventure for my son and I. We love to kayak. I'm a proish photographer and am teaching my son the hobby. We have travelled all over the US doing these things.
I am considering kayaking the Rio Grande with him. I understand there are about 250 miles of river. I'm trying to find someone who has done this before and would be willing to act as a kind of guide for about a month long trip. I'd like to be able to stop whenever and wherever for photo opportunities and such.
I've checked out some of the services offering guided trips and they run about 5k, but include everything. I'm looking to supply my own kayaks, tents, food, etc. I just need someone who is experienced with kayaking that whole stretch and knows the area really well.
Thank you for your help 
Johnathan Cobb