There's no need to "bolt in" SSDs, as they have no moving parts. You can run the thing sideways, vertically, diagonally, upside down -- it really doesn't matter. Just get some velcro kits from your local hardware store and call it a day, or even two-sided tape.
Maybe it's just me, but you'd really be better off junking the old case and running caseless until the owner (not sure if you) can afford to replace it. That is, unless you enjoy spending hours upon hours modding that piece of crappola in the pic when you can just get another and be done with it. And I'm talking more for airflow and expansion purposes, less esthetics. There are some great cases out there for $50-100 USD, and if you can afford an SSD you can probably afford that as well.