HD ...stops at grey screen logo startup

I changed the permissions from read only to read and write on my start up HD and chose the change everything inside option to read and write. After I did this, my secondary HD no longer allowed me to use it saying I did not have permission. When I tried to change it all selections were in custom mode and would not accept my changes. Same with my main HD. I rebooted and the grey screen shows up with icon and no spinning wheel. I tried safe mode...same thing. I even tried booting off my back up firewire drive and got a null sign on the grey screen instead of an apple icon. Booted up from the G5 disk and tried to run utilities permissions repair and it would not do it, gave me an error, “No valid packages”. Ran disk repair and it said nothing needs repairing. I then booted up using Disk Warrior and rebuilt the HD’s directory successfully, but still the G5 will not boot past the icon grey screen, no spinning wheel. I’m spinning though...HELP, I'm dying here.
FYI this is a G5 dual core 2.3, 3.5 gigs ram, running leopard, 250 gig HD

Lesson learned here? Don't mess with permissions that you shouldn't be. Use your original install media and reinstall Leopard. Hopefully you've been making backups. If not, then purchase a data recovery program such as Data Rescue 3 and hope that it can recover your files.

New issues

Thanks for your advice. In fact, the two firewire drives connected to the computer at the time were my back up drives in place to perform a back up. I did a archival reinstall and that worked for getting the computer back up again in Tiger. I have to now upgrade it to leopard. However, my other internal drive and both firewire back up drives will show up on the desktop. Disk Utility shows them there and healthy with only two problems. The names I gave these HD's all have a piece of paper for an icon now insted of the HD icon and the info at the bottom says the drives are empty. I checked them with Disk Warrior and DW shows the info there, but also acknowledges them as not showing up on the desk top. I even tried the externals on another computer and they have the same issue. Please advise.

ps Lesson learned!!!!!