I’m editing 8 concerts shot with (6) HDCAM and I’m editing with multicam with the footage captured as DVCProHD. I built my own Raid system with SATAII drives and cards. Sonnet Fusion 400 enclosure with (4) 300 GB drives and I just swap out drive sets when one is close to 70% full. I get 250Mb/s read speed and have no problem pulling the 6 streams. Of course you put 500 or 750 drives if you need more capacity at a time.
If I wanted to I could recapture the show in HDCAM while picture was locked as Uncompressed HD and everything would work fine.
NOTE: 2hrs of 10 Bit HD would be about 1.2 GB.
So it is all doable, for about $1500 you can make it work.