Map Ideas? I'm not sure I fully grasp what you're asking for here, and i'm sorry if the answer i'm about to give you has already ben stated/done, but It's just an idea for a 'map' that's been on my mind for a while, With that being said, here goes!
I think there should be an Modded Minecraft survival Island. Where you have a quest book with multiple quests to guide you through to 'end game'. It would be unique if there was another mod that would alter the world generation to spawn one single island, with Ocean on either side for..... 30k? blocks, and beyond that, normal land. This will make it extremely difficult to swim to land to gather resources, basicly forcing you to do as the modpack would intend, survive, on the island... However; there would be ANOTHER mod, that adds a 'special' boat system, that when you build a large shit, a sail boat of sorts, something that could take hours and hours to build, then it would then allow you to use said shit to quickly navigate to and from your island, but this boat would have to be made an near end game type of item, so that people can just join the pack, kill a few sheep, cut some wood, build a boat, and sail away, instead, the mod would add a block to the game that acts as the 'engine' (if you will) for the sail boat. (Engine, on a sail boat, *Facepalm* For lack of a better explination, it will have to do for now). Said block would be very hard to craft, and take multiple extremely hard items to craft, thus making it near end game.
From the sound of it, this type of mod pack would atleast need 2 new mods, the world generation mod, and the sail boat block mod.
Also to clear things up, when i said "Sail boat block", I didnt mean, it's just one block you place, then a boat appears, you'd actually habe to build the boat, and not something like a 5x5 little wimpy boat, i mean a massive like 20x100 boat will full sails, something that would look like an actual pirate ship..
Sorry if my post is all over the place, and if I rambled a lot... I hope this is kind of what you were looking for, I personally would enjoy a FTB Survival island, speaking of that, does anyone have any links to a FTB friendly survival Island, or a seed to one?