You could probably use pretty much any 16-bit card if there was a driver for it. However, most devices don't have software for them... I don't know about any of the PCMCIA CD-ROMs, but have a look for device drivers on Aminet etc.
The largest memory card you can use natively is 8MB, or 4MB if you've a low-end accelerator or memory add-on with 8MB on it. Higher capacities aren't supported natively, but cfd.device might let you use them - it works well with compact flash adaptors.
