Hi Crunchberry,
I'm sorry to hear that your son has RSD

. I also suffer from RSD type 1 in my left leg and right arm, I developed it when I was 12 years old and am now 13. I know we have PM'd eachother so I wont go into that many details has i've already told you most of them - if you have any questions that you need answering, please let me know as I know how scary it is dealing with such an horrible condition at such a young age.
About what sort of Doctors to treat RSD, you would probably be better seeing a Pain Management Doctor as they often prescribe pain meds and things that can help. Neurologists don't seem to know that much about RSD so they usually refer you to another doctor (that's what i've found anyhow).
The most important thing is that you see a doctor who knows about RSD and is compassionate. The worse thing you can do is see a doctor who claims he/she knows about RSD when they actually don't as they can often make things worse. PT's are also good at treating RSD but again, you really need one who treats RSD and other chronic pain conditions.
If your son's doctor wants to do a nerve block, make sure he knows what he is doing and that he DOESN'T inject into your sons back and limbs that are affected.
I have heard that Cleavland do an inpatient PT program that can be useful sometimes so maybe that is something for you to look into. Also Dr Sherry in Philedelphia has good results - I have spoken to a lady who's 11 year old son had RSD in his stomach and Dr Sherry's program made his RSD go into remission!
I hope you find a suitable Doctor real soon and that your son gets to feeling better. The good thing for you is that if your son has RSD (and I really hope he doesn't), it was caught easily and he is also still a child.
Take care and if you need anything, me and my mum are here.