What timing, I've literally just been doing this for my 630.
So in answering your question, it really depends what you intend on what kind of CDs you want to make, the burner and (half decent quality) CD-R's shouldn't matter too much (avoid RW's though!).
With ISO files and most other disc images, you should be able to burn them on any machine and/or configuration that can handle the files (for example, I use PowerISO for Windows).
If you want to drag and drop files and use CDs like a thumb drive (that once burned you can't re-write obviously), then that's more tricky.
To achieve this you need an OS that can handle plain old HFS (not HFS+).
The last OS to support that legacy is Leopard, and if you don't have a good DL burner, it's a bit of a pain to install (possibly impossible on most modern Mac's too).
I managed to get Leopard on my Mac Pro 3, 1.
From personal experience, my external 600 drive hates them, and the 300 / 600 internal ones seem to mostly read them ok but not always 100% successfully, often having a bit of 'data garbage' that you never intended to add.
There's loads of tutorials on how to do this. Il link you to them of nobody else does in the next 24 hours, but right now it's half 3 in the morning and I'm about to pass out.
One thing I will say is I strongly recommend that you burn at the slowest speed possible.