Is it possible to...

[KoncreteLiquids]

Get the old modpack and map from direwolf20's first FTB multiplayer map found here and play it single player?

 

[Vovk]

try FTB retro SMP v1 for 1.2.5 in the launcher?

 

[KoncreteLiquids]

I dont know if that is the same modpack but what about that level? I can launch SMP V1 1.2.5 but I dont have that map

 

[Bibble]

I believe that the maps that can be downloaded through the launcher are the pyramid versions. If you want to install the 1st one, you'll need to find a copy of it (I can't remember whether or not it was released), and put it into the saves folder. There shouldn't be any major mod conflicts, as I recall.