I agree with Patti about SSD, it's more of a nuisance than a problem. Yes you do lose directionality and it's hard to figure out where sound is coming from most of the time if it's from behind you. But not that troublesome,, agree it may be more so with a young child.
The BAHA device is made by Cochlear and Oticon Medical. Both are similar but not interchangeable. It stands for bone anchored hearing assist (device),, it is basically a small processor that attaches to a titanium post that is implanted in the bone behind deaf ear. Relatively simple procedure often done in the Dr office or as out patient. I have had mine a little over 2 years. It helps you hear from the deaf side by the processor transferring the sound through the post into the bone and then it transfers to your good ear to actually be heard on that side, , too involved??
,,, that's the concept anyway,,,
It's may be worth looking into if you become SSD ,, some people live quite happily with SSD. I did for 3 years. You can "try" the processor on a headband generally at most offices that deal with them. It's not the exact same as having one,, but you get the idea.
Hope this has not been too long and boring but wanted to answer some questions you had,,,