Need to upgrade OS to 10.5.8

Here is the situation. I currently own an iMac flat panel G4. I use it for running my software at my salon and that's about it. I recently was told that my software company is doing upgrades for my online services and my current computer is not up to par. Here is what "about this Mac" states:
Processer: 800 MHz Power PC G4
Memory: 768 MB SDRAM

According to the software company this is what I need:
Mac OS X
PowerPC G4, or G5 or Intel processor
1 GB (Server / Stand-alone)
1.5 GB Hard drive space
OS X 10.5.8 or higher (Server / Stand-alone)

Can someone please tell me if it is possible to upgrade my processor or memory on this computer? I really don't know that much about macs since I have only been using them for about two years now. I really need to find a way to not have to purchase a new computer because I can't really afford to right now.

Well your G4 system could be upgraded to 10.5 and the memory could be increased to the 1GB but you are stuck with the processor you have ... I think they are soldered in to the system board... I could be wrong

It may be cheaper in the long run to upgrade and get a new system

If you can't get the new intel (as they are $$$).. (depending on where your are located) you could try craigslist .. won't be new but would be new to you and you could go physicaly check out the system. before you purchace it.

Apple's official position on this is that you need a minimum of an 867mhz cpu to be able to upgrade to 10.5.

- Nick