Search on eBay for SiliconTech
You might be lucky and find an 800mb solid state hard disk that
will plug into your SX-1 and give you zero noise and super fast
access.
For memory get an 8mb single-sided 60ns 72-pin SIMM (non-parity,
non-ECC). Get a Fast Page Mode (FPM) module.
Get a Goliath Power Supply or a Wizard Power Box if you can or follow
tips on Aminet how tomake your own PC supply.
You might also want to benefit from the SX-1's ability to
simultaneously use the CD32's Full Motion Video VCD card.
Get yourself a mouse and keyboard too! The Wizard 560dpi mouse is a
good one, but any old mouse will do for now as long as it's Amiga
specific.
:-D
Enjoy!