I think it’s best to avoid playing mods since they are often a matter of personal taste and it’s best to leave it as vanilla so that everyone is on the same page. Also, as Regul says, stability is an issue and losing months of progress to an update will be a bit of a killer.
How many players are looking to restart? We have 8 players, 2 who need some DLC and 2 who seem to be out of touch? The availability of players is going to dictate the map size and game speed. Since this is supposed to be the “Forever Game” I’d suggest the attempt is made to bring the player base up to 12 again, but play the game on a Large map so that we have some border conflicts. I believe that there is a work around that allows adding of additional players to a hot-seat game but it requires some editing of the XML:
http://forums.civfanatics.com/showthread.php?t=431821
I’d also suggest setting it up on Epic Speed to keep the game moving, possibly even Standard though it’s moving away from the concept of “forever”. I think Marathon will just make people lose interest (start building wonder, turn skip for the next half a year – not really that fun).
I like the idea of scarce resources to enforce trading/warring.
My vote for map type would be small continents, low sea level, default all other settings. That should give all civs, sea and land based, the chance to shine while forming some interesting shaped continents that stand a good chance of being connected. An alternative would be Large Island, Low Sea level. While this would ensure that everyone could be reached before Caravels, it does put the favor back in the court of the sea based civs. Also, I dislike the Plus maps just because of the CS placement. I want to compete for tactically place CS, not just throw money into the sea for fabulous prizes.
We need to find out the time zones for the players so we can optimize the turn order as well.
My 2 pence