If you were to get an SX-1 for the cd32, you'd have to make a bootdisk that disables fastram, or unplug the sx-1. I think the promodule has a switch to disable fastram, but I'm not sure about the sx-32.
I had done extensive research before this post. The SX-1 does in fact have a Memory disable jumper, which I assume would mean opening it up all the time: bad. The ProModule has a Memory disable switch. The SX32 Pro has a disable switch but I'm not sure what for. I found all this out here:
And you never actually said which you think is better: getting an A1200 or an SX-1.