Wow. It took a long time for me to even remember this thread. Boy, times have changed.
In the end, I believe I routed long internal SATA cables through a slotted backplane insert, and used SATA to eSATA adapters.
I would say it worked quite well -- although I was never really comfortable with the mechanical "play" of the adapters.
I would say that maybe 2 or 3 times, a drive would fall-off the array -- but I was never completely sure of the reason.
When that happened, I rebooted the computer (having made sure the adapters were secure) and the RAID volume reappeared -- and I'm not sure the adapters were to blame.
However, there many RAID solutions that will continue to view a volume as degraded when that happens -- even if all the drives are reinstated.
Fortunately, my RAID solution was more tolerant.