ajax, welcome to Apple Discussions & the Mac community.
Need to know what model iMac you have. If you can boot to OS 9.2.2, under the Apple menu, open Apple System Profiler. Tell us what MHz, how much RAM, what size hard drive. Does it have a CD disc drive or a CD/DVD disc drive?
Look at the specs on this page to see if you can determine which iMac you have.
http://www.everymac.com/systems/apple/imac/index-imac.html
Here's the Panther & Tiger requirements.
Mac OS X 10.4 Tiger system requirements @
http://docs.info.apple.com/article.html?artnum=301341
OS 10.3 Panther requirements
http://docs.info.apple.com/article.html?artnum=106163
Panther install CDs and Tiger DVDs (some on CDs) are no longer available in brick & mortar stores, but are available at web stores & eBay.
You need to check if your Mac requires a firmware (Boot ROM version in System Profiler) update.
Mac OS X: Available firmware updates
http://docs.info.apple.com/article.html?artnum=86117 If an update is required, the update must be installed (using OS 9) BEFORE you install OS X.
Cheers, Tom 😉