I developed RSI (tenosynovitis), similar to carpal tunnel in both wrists a few years ago, so I certainly can understand the need to want to switch to speech for coding.
Unfortunately there's really not a lot out there that gets the job done in a decent way - as has already been mentioned code navigation is extremely frustrating by voice alone, and the wide array of unusual characters us programmers need just don't help the matter for general use!
I personally used Dragon Naturally Speaking for around 3 months but eventually decided that it simply wouldn't work as a long term solution. It was suggested to me by a physiotherapist to try an ergonomic keyboard, Maltron (with the Maltron layout) specifically. Considering that I cripple in pain with a standard keyboard I can now code pain-free all day long. They do (or used to) a rental model so that you can try it out. Even if you're not in a position to be using a keyboard now, it might be worth considering in the future.