Hi, I use a PIONEER CD12x Cd-rom and my EPS16+ has no problem reading Ensoniq CD's.
I use too, a ZIP100, and works as well but if the CD is conected. (Needs some supply).
For other like your Syquest, find the Rubber Chicken link in this web.It's very informative and helpful.
The memory you already have in the EPS16+ module is the maximum possible. 2M and with the Flashbank another 1M.
Hope it can be af any help.
Gabriel.