Hey Rich,
Might be a long shot but we've got a copperized system at the Pet Boutique that works wonders on ich (it seems like every tang...).. If you like you can pop by with them and they can do into one of the partitions for a while.
Normally I'd be a little leery about putting new ichy fish into the system but we've had a wee bit of a problem in one of our displays so there's going to be ich in there anyways come tomorrow.
I just spoke to John and we're not too sure how the eel would fare in a copperized system (anecdotally they've been fine, but in the literature it says that's a no-no) and sounds like the cow would be hard-pressed too, but the hypo system might be a good answer.
As far as I'm concerned you can have them back when they're better - beyond gobies and tangs we don't sell a lot of other marine fish so they'd probably end up sitting there anyways.
John will be in the store tomorrow until 3, and we'll both be there all weekend - give us a shout if you want to give it a shot, 604-688-7387.
Cheers,
Stefan