definately sounds like the hdd died,,, like you said you've been having problems for awhile.
when hard drives die they tend to make a clicking sound. there is no way to save it and even if you can get a little info off of it you will not want it as it will most likely be corrupted.
i've never dealt with slayers before so i'm no help there but have you tried AID? it is the program i use, i just put it into the system after installing a new hdd and it formats it and everything i need.
if you are trying to get the 10 gig to work then you might have to put it into your pc and reformat it and try the install again. i had a problem with a new install once where everything seemed to install correctly but when i rebooted the system it just froze at the boot screen. couldn't load the dash. i had to reformat it using my pc and do it all over again before i got it to work. it was a problem with the dash i installed.