A little update:
I bought the Godshark 44-pin SATA-to-IDE
adapter to go along with my Kingston A400. The inner components of the A400 are protected by four Torx Security screws. Unfortunately, I did not have anything on-hand to open those screws, so I had to 'get creative'.
Anyways, the SSD out of its enclosure fit perfectly in the Mini with the adapter. Initially, my Leopard USB installer failed to detect more than 32 MB or so on the SSD, but after I reformatted with APM it seemed to work. Weirdly, it prevents me from extending the partition beyond 128 GB. I wonder if it's because I installed the OS 9 Drivers? I had trouble getting this SSD to work in a Dell Latitude D530 (with no adapter) so I will monitor any anomalies I see.