I do understand that IC is a very uncomfortable and not easily treatable condition. However, I still wonder if radical cystectomy is the right solution. Also, I suspect that you are female (as IC is much more common in women) and neobladders are not necessarily a good option for women; they are much more likely to be either incontinent or hypercontinent with this surgery. If you do decide on cystectomy, an Indiana pouch might be something to consider.
As for recommendations, You would need to find someone who does LOTS of these surgeries as the expertise/experience of the surgeon is a paramount factor. You should consider places that specialize in bladder cancer such as MD Anderson, Memorial Sloan Kettering, Stanford University, USC, or Johns Hopkins to mention a few.
You should also explore the doctor's knowledge/experience with intersitial cystitis.
Sara Anne