Finding a skeleton that matched the base avatar, Ruth, was what I had in mind. I have no problems rigging or uploading, but simply was unable to find something that matched Ruth's shape. Somehow I missed Gaia's skeleton—that seems to be exactly what I was needing. I would've loved to have built around my own shape, but the plug-in that exported that and the skeleton combined didn't work for my software, and with the deformer project on the way it was easier to plan for the future and build around Ruth instead. Thank you for pointing out that other skeleton. I have a folder crammed full of different skeletons I've found but somehow managed to miss that one.
I tested by rigging and exporting Ruth's chest and then attaching it to Ruth's chest--I put a Ruth on my Ruth because I like Ruthing while I'm Ruthed. Ahem. Another thing to keep in mind for those who work with Maya: check your import settings if you can't get the SL uploader to see your mesh as a rigged mesh. Import defaults will append the name of the file you are importing plus a colon at the front of every bone name.
edit x3: multiple formatting failures. I'm awesome.