iMac far from audo rack - any suggestions?

To go from Imac to a remote DAC, you can use an Airport Express.
That's what I do. I run the AE to a Cambridge CA840c using Toslink.
The AE output is either USB for printer only...apparently and the miniplug which is either earbuds / cable +splitter OR mini Toslink. EITHER from that port.
ONLY fly in the ointment is the clocking from the AE is a little wacky. My CA doesn't like it and no matter what I send it, it periodically goes out of synch.
CA has sent me the 'fix' in software for there player. I now have to nerve up and use my Serial Null-Modem cable to make the connection and use the software package CA sent me. As an aside, the dealer I bought from wanted to CHARGE me to do the upgrade!

Does the static sound Ejlif gets really glassy and like a finger nail on a chalk board? Never in the same place twice on same tune?
COULD BE your DA simply doesn't like the AE or other Apple clocking. I think the clocking may be the issue, NOT 'static'. Consult your DA's maker for any software or upgrade.

I think people should start putting the heat to APPLE since I thought I was the ONLY ONE to have such difficulties.

Yes, and they are dirt cheap, too.