Success!!
I think the burn speed may have been the key but I did try a couple of other things which may have helped.
First off all I used the D2pro 9 EUR 1.6 Utility disc (burnt onto a Verbatim at 2x) to update the D2C2s firmware to 1.6 (you cannot update a chip installed on a D2E according to the D2pro site).
I tried the SSB ISO burnt onto the TDK at 2x and it would not work, neither would the GC ISO on the Mini DVD. I read a few threads about burning discs and i learned that sometimes burning too slow can cause problems so I burnt a Mario Kart ISO at 6x using ImgBurn onto a Verbatim DVD-R disc. I put it into the D2C2 and I got the splash screen, I wasn't expecting it to load but it did

I had to update the system from the Mario Kart disc for it to run (ignoring the mod chip warning, the Wii cannot see the D2pro, I'm not sure about other chips though, be warned) but it works great now

I'm still having problems getting GC ISOs to run but I can work on that.
The 6x Verbatim Mario Kart disc also worked on the D2E Wii but didn't require the system update.
The funny thing is the 2x TDK SSB disc now works on the D2C2 but not the D2E.