err.. ok yeah where do I start?
This is the wrong section for a challenge, needs to be in 'Challenges and Activities' section.
It's kinda odd picking the exact same idea, as I don't think anyone would be as up to it as they were with the first. Thinking up something much more original would maybe get people willing to join in.
They've just finished the other grid (well almost), and I think it's too soon for a whole new one. It's like commin to the end of an epic story, and havin to re-wind it to the begginin cus one person wasn't watchin.

Proceed with this by all means but I personally would just think 'ahh well' and wait for something else to come along.. Enter another challenge, or if ya just like Iso, fill a smaller one in yourself...

Goodluck with this anyway.