I suppose I should update this thread.

I finally got around to making my MDD a storage server & DLNA streamer for my PS3.

I found that newegg has kingwin IDE to SATA adapters that had good reviews.

I picked up two adapters, and two 500GB SATA hard drives for under $100.

The hard drives plus adapters won't fit in the original space - period. I probably should've known this but I thought there would at least be an inch... not so much.

So I decided to run the G4 without an optical drive. This setup is working fine - and the adapters make the drive show up as an IDE drive (!) complete with SMART reporting.

Speeds aren't record breaking though. I ran xBench to a tune of 12MB/s. Sucky, but i figure there's loss in translation.

I plan on eventually getting a SATA card and flashing it but since I don't know what works with what then I'll just use this until I get more info.

Video streams fine from the MDD to my PS3 so I'm not too worried about it. The CPUs do jump up in usage when streaming, but it's never choppy.