OS X :: How To Upgrad G4 Operating System?

I have a mirrored drive door G4 [dual 1.25 GHz] with 10.2.8. The newest browser I can run is Firefox 2.0.0.20. That browser will not successfully run some sites. Monster.com, for example.

I am unemployed just now and cannot afford to spend money on a new Intel machine. I have critical need of being able to run what I have here now:

Photoshop CS [no number suffix]
InDesign 3.0.1
Microsoft office X, 10.1.6
Filemaker pro 6 [although I do also own 7]
Text Soap 3
Roxio Toast 5.2.1

I have been told I could upgrade this G4 to 10.4. Supposedly that would allow me to run a current browser. I don't know if that is true, it is just something I was told.

I have multiple fears about making such an upgrade. First, where would you get the discs to do that, and how could you get any patches or upgrades that were created subsequent to its introduction?

Second, would all my software listed above work with 10.4?

I imagine I would need to make up an external drive that completely mirrored my current setup, in case it went wrong and I had to go back to what I have.

My need is to have a computer I can use to look for jobs effectively. Monster.com won't even let me log in with this browser. I consider buying some used machine with a current browser to use for my job search, but hate to waste the money.

Do the experienced and knowledgeable here have some advice for me? Is there a safe way to make some changes on this machine and retain my current array of software?

As soon as I get a job I will spend the money [I currently have saved] to buy a new Intel Mac. I just don't want to let that money go while I am unemployed. I have been for three months and have not gotten so much as a single interview.