Pre purchase advice

I am looking for a device to help me out. My problem is I am a recovering from paralysis. I was paralysed from the chest down and still have some issues (numbness, difficulty peeing, poor quality erection if any, loss of bladder control, and diminished ejaculations).

I am really trying to tone my pelvic muscles. I read the entire aneros site and couldn't tell if these things would help firm up these muscles, or if you must have good tone in order to use them. The motion made to stop the stream of pee (same motion to ejaculate) is difficult for me - the ones I do are weak and extremely tiring. Would this device help me to do more of them or help me build up tone to do more?

Having better orgasms would be great, too. I'd be happy if I could just build up enough strength to control my bladder better though.

Next question - what size should I need? I am 6'1" (185cm), 190 lbs (86kg). While I don't have have great external feelings in many places, my anus does have a lot of feeling, as well as my prostate (I can feel more internally now than I could before being paralysed). My doctor cannot explain it, but I seem to be able to feel more internally - like 2 inches under my skin than I can on my skin (this makes for some rather interesting experiences). I also don't have great rectal tone - meaning that when my sphincter is manipulated, it relaxes and I basically have no control or ability to tighten it immediately - it must do that on its own over a few minutes. This is another thing I hope using the aneros might help with.

Given all this info, I'd appreciate any feedback on whether the aneros might be of any help with muscle/sphincter tone (not only the anal sphincter but also the bladder sphincter), and if so, what size should I use?