OK, the maps listed here are even bigger,
http://forums.civfanatics.com/showthread.php?t=179969 , well at least some of them, sizes are listed, and if they have starting points or not also, it also tells you what to do if you want a 23/24 civs map also. But the way i put civs on a map is using MAPVIEW. With mapview i get the locations and then with notepad open the map i want and place the starting points to that location(s).
If you want some challenging maps try these,
http://forums.civfanatics.com/showthread.php?t=182772 some are really really hard, especially the bigger ones, but better make sure you have the processor and memory they tend to lag in late parts of the game otherwise.