Upgrade from 10.4.11 / keep Classic?

I am using system 10.4.11. This is the hybrid system which allows you to run system X and Classic also. I would like to upgrade my system to at least snow leopard, but still keep Classic.

I am running a Power Mac G5, and have three system 9 applications that are critical to my business.

Is it possible to upgrade just the system X part of the system, or will Classic simply disappear if I do?

You cannot upgrade that system to Snow Leopard. Snow Leopard requires a Mac with an Intel chip. According to Wikipedia you have the last OS that will run Classic. See also Apple quietly disposes of Classic in Leopard | Ars Technica

What apps are you needing to run in Classic? I loved the G5s but its been a while since they were in their prime. Perhaps there is an alternate program out there that would not require Classic.

How do you tell if you are running a hybrid system? I have an ibook G4 with Mac OSX 10.4.11 and need to run a program in classic. How should I go about doing this?

If I remember correctly there will be a preference pane in System Preferences. It has some settings for when and how it loads.