They already left my iMac G4 out in the cold. OS X 10.5 doesn't work on G4's below 867MHz and my 17" iLamp G4 is 800 MHz.
I had the same thing - and was salivating over Leopard for so long before it came out that when they sprung that 867MHz requirement on me I jumped and got a 20" iMac to be able to use Leopard.I gave my G4 to my daughter for the granddaughters - they love it. When I was visiting them recently and tried to use it, I found that I am thoroughly addicted to the 20" screen and to the expandable text windows in the Leopard version of Safari.
You can download and install Safari 3 on your old G4. It has the expandable text windows. Unless you have a screen stretcher (Pat. Pend.), I can't help you with the width of the view...