Thinking about getting a nomad. Thinking I need a lightweight camp bag made out of same material as tents. Zipper down the center. Any companies make something like this with material like this
I don't know of any that make it exactly like a camp bag. I think many people are going with a dry bag as their "camp bag" and Outdoor Research makes a 55L one that a lot of people are talking about using. Granted, it doesn't have a zipper down the middle though but it is truly waterproof.
Now, you can also go the DIY route (fitting for your forum handle) like this one that I made out of silnylon. It has a waterproof zipper and should be fairly water resistant but definitely not waterproof.
Here it is loaded into a Nomad along with a back pouch and then with "camp dropped"
There is also the HPG bag that can be seen in this thread too with more pictures but it doesn't have the zipper either.
Oh, and I guess I should just mention you could always just use a duffel bag or something else too. The two big questions or requirements that you should think about would be whether the zipper is truly needed and if waterproofness is needed.
It's 12x24x8 so I think that comes out to about 2300ci. Basically I based it off the pullouts I was building and since the they all square of and fill the void, it works quite well.