If money is an issue, i pod Touch is a bit cheaper than the i phone, same size touch screen. You can run the same app, Speak it, on it but of course you can't use it as a cell phone.
If you don't necessarily need the "voice" feature. If you are happy to be able to type something and have the other person read it you can use an android "smart" phone with a program called Deaf note, which is free to try and less than $5 to buy and works very well. As far as I know there are no android apps out yet that works as WELL as Speak it but the app talka droid works semi well.
The key is to get a touch screen large enough to be able to easily use but small enough to be more portable than the i pad. I tried the i pod touch/ i phone 3.5" touch screen and found it too small for my short fat fingers to work easily. I still have full use of my hands (bulbar like your husband) but just found that size touch screen key pad too small for me to use quickly, I had too many mistakes. I bought a sam sung galaxy S 2. with a 4.3" display and in landscape (turned sideways) I can type pretty fast with two fingers. I do okay with one finger in the vertical position. The sam sung galaxy S 3 has a 4.8" screen and that does make it easier still to use but costs a bit more. If those are still too small you can get the Samsung tablet model called note with a 5.3" screen that can be used as a phone as well but is pretty dear but would fit in a shirt pocket but not a pants pocket. It all comes down to how small a screen you can physically work and how much you are willing to pay, if you need a cell phone and if you have to have apple apps or can make due with android apps. I would hope a good android app such as speak it will be out soon. No I don't work for sam sung. lol
