OS9 Browsers to try...
WamCom...
http://www.wamcom.org/
iCab...
http://www.icab.de/dl.php
Classilla...
http://www.floodgap.com/software/classilla/
If you can Install OSX 10.4 or 10.5 then there are better Browser options.
TenFourFox is the most up to date browser for our PPCs, they even have G4 & G5 optimized versions...
http://www.floodgap.com/software/tenfourfox/
I'd avoid version 24 though, as it no longer supports plug-ins like Flash.
http://code.google.com/p/tenfourfox/downloads/list
SeaMonkey seems pretty fast also, with many options...
http://www.seamonkey-project.org/
http://www.seamonkey-project.org/releases/
The last version with Mac OS 10.4 and PPC support was SeaMonkey 2.0.14.
The last version seamonkey-for-ppc - 2.26 RELEASE - Mac OS X 10.5.x - PPC.
For Leo/10.5.8...
https://code.google.com/p/leopard-webkit/
http://nightly.webkit.org/
http://code.google.com/p/leopard-webkit/downloads/detail?name=WebKit-537.3.1-Leo pard.dmg&can=2&q=
http://code.google.com/p/seamonkey-ppc/
PROJECT SITE:
https://sourceforge.net/projects/seamonkey-for-ppc
register for updates at the SourceForge seamonkey-for-ppc project page
https://sourceforge.net/projects/seamonkey-for-ppc
Might also look into iCab & OmniWeb versions.