I recognize that I've veered off the original topic of an OS-less firmware update but I figured I’d close this out with an update on my status. I was able to get 2 copies (10.6 and 10.6.7) of Mac OS X install DVD’s. 10.6 causes a panic while 10.6.7 gets to a point where it simply says “OS X cannot be installed on this system”. No other information given.
As a last ditch attempt I booted to a diagnostic disk to run some tests and verify that the replacement hard drive was, at the very least, properly installed. All the tests came back good, except that none of them mention a hard drive at all, not even in the hardware profile where it lists everything.
I’ve given up. I’ll be a lemming, waddle over to the 5th Ave store and want to shoot myself for being there. Thanks to wjosten and Shootist007 for the replies.