Moe Mansion is a bleeding edge version of srb2kart based on birdhouse
This version merges changes that aren't fully tested so there might be some issues from time to time

Usually you only need to download srb2kart.exe.
The dlls are only needed if you're changing from 32-bit to 64-bit or viceversa.
You know if you need them if the game crashes as soon as you start it or it says it couldn't find a certain dll.

If you don't know which version to get go for 32-bit. 
64-bit is reserved for people that know why they need it and don't need help because there is 0 support for crashes on 64-bit as they don't produce RPT files.
If you need help always use 32-bit.