iMac 20inch (Mid 2007 Build) with Ubuntu 12.0.4

How I got in this situation

I had a perfectly healthy Intel iMac running Snow Leopard several months ago. Then I got the dreaded spinning gear and several kernel panics. After getting a little frustrated (failing to find a solution online), I found an old macbook installation disk and used it to access Disk Utility.

From here, I erased my entire hard drive leaving me with no OS. I then created a Ubuntu DVD and installed Ubuntu onto the system. Now, on Ubuntu, I wine installed Transmac and burned a Single layer copy (with languages, etc. removed to save space) of Snow Leopard onto a 4.7GB DVD. I tried to boot from it and was met with first the grey apple screen and a spinning cog before the grey apple shortly turned into the infamous prohibitory sign.

Note: I met this problem previously when using Disk Utility to create a bootable USB of Snow Leopard, hence I severely doubt it has anything to do with the DVD created.

Resources at my disposal

• 1 x iMac running Ubuntu
• 6 x 4.7GB DVDs
• 1 x USB Stick 12GB
• 1 x Windows 7 Laptop

Resources I do not have

• Firewire cables
• Access to a prebuilt retail disk (Misplaced)
• Access to another Mac
• Apple Warranty

I would be hugely grateful if someone was able to tell me how to install Snow Leopard again.