I also prefer 2nd setting, the only difficult part is to decide on the tombworld name and who is gonna be the necron lord ^^
Well my vote goes for Urian as the Lord. I have born witness to a number of RPs in which Urian participated, his writing abilities are superior. Plus the role of Lord will require a bit of GMing as well. and as for the start... well I think for option 2 to work the RP would need a skilled manager.
Ooh, I think we're soon ready (a bit late but still). Now, my dear friends, make you characters and hope that Urian takes his place as the lord!