On all these issues, I'd say talk to your local council! There may very well be some statewide or regional jamboree-type events you may not be aware of! For example, we have a statewide event called MassJam every 4-5 years (Mass and RI). Your council should also be able to advise you on the sub-camp idea!

National Jamborees are every four years on average. The best description I have given to people who have not attended is "half convention, half summer camp." It is the BSA's one national event that brings Scouts from across the BSA together under one "roof." It is just BSA members and (if memory serves) units from other WOSM countries. Girl Scouts are not included but Venturing members are included for the first time in 2013.

As far as finances, it depends on in what capacity you want to attend. It looks like you are pretty close to The Summit (West Virginia) so travel costs will be cheaper. If you attend with your council, you will have a much higher cost than if you attend as a staff member. You also have the option of visiting for a day instead of staying for the whole time.

If memory serves, there is not a subcamp specifically for deaf Scouters but there is a "Disabilities Awareness Center" that addresses blindness, deafness, and other disabilities. I've attached the staff position description below if that is something you are interested in pursuing.

Disability Awareness Challenge
Seventeen fun and challenging exhibits and hands-on activities which will give participants the knowledge of and sensitivity to the various types of disabilities. This experience will enhance their understanding of what those who have special needs/disabilities go through on an ongoing daily basis.

More information here: https://summit.scouting.org/en/Jamboree2013/Pages/Staff-Position-Description.aspx

I think the "hearing challenged" subcamp idea may have merit. If it is not too late to plan for such, you might contact Irving (National Council) and ask for the Jamboree Director's office.
I know the Disability Awareness area was very popular at the 2005 NJ, at which I staffed. I visited that area more than once and had some good conversations there, talking about growing up with a dad who had lost his left arm before he met my mom . Among other things, I learned how to tie my shoes one handed.
I think they might be concerned about numbers (small?), but I know that deaf kids do like to hang out with folks that are easily conversant in ASL or Signed English. I dated a young lady who was a counselor at Gallaudet, and gained some insight thereby.
Then too, such "segregation" might not be welcome, but it is an idea to discuss, if it is important to you.
There were at least Troops, if not whole subcamps, that were "specialized" in various ways. Why not an ASL Troop?