Having experimented for the last few weeks on this issue I can speak with some authority.
1) Spinning rust hard drives are hot and unreliable (as are Zip Drives...well they're not hot but I swear mine could have caught fire this week as that died)
2) SD2IDE cards don't work well for 2 devices on one data bus as they default to Master and like to hog the bus. Zeb's WHDLoad image seems to bypass this to some extent but your other device will have to be slave.
3) CF2IDE Solutions are FAR the superior solution. The media is more expensive but a 8GB Industrial Grade 'Extreme' (fake SanDisk brand) seems ok for £19 on Amazon! Get a good controller with a Slave/Master jumper and you are away. I found one with both a 44pin and 40pin socket! Awsome!
