[Chris Kean]

What Avid product are you using? Assuming it’s Media Composer v.5.x, have you tried to link the XDCAM EX media with AMA? I don’t work with EX footage, but MC 5.0.3.2 should play it just fine (AMA or import).
I would definitely try exporting prores then link to AMA files in MC if you can. I no longer use the animation codec. Im not sure i understand this mandated codec thing you mentioned… but if you can give this way a try… if it works, you save yourself ALOT of hassle going back into Media Composer. Then, export whatever you need as a delivery codec from MC.

As for the color space, I convert my color space prior to exporting from AE. I dont have a scientific reason other than I just want to make sure i don’t get any surprises downstream. Perhaps someone here has better way for better reasons.

[Chris Kean]

Brad,
I think most of us have been in your shoes at one time or another. As a former NLE integrator, I would highly recommend taking your system and all of its disks to someone who builds/ maintains these systems. I mean no disrespect at all. NLEs require some pretty high performance and sometimes don’t really have a high tolerance for random hardware or software problems.
Im not really a big fan of recommending a whole new system without knowing if you really need it. I have revived more than one d.o.a. system. Ill bet a couple days at the doc and she’ll be better than new!
Good Luck!