Questions from a beginner about Step Mania

[Lehmeiers]

Hello!
I'm looking for a game like Dance Dance Revolution and found Step Mania.
I have a few questions about it:

1. which controller do I need, is there one for dancing and where can I get it?
2. where do I get the songs?
3. how difficult is it to create your own songs or favorite songs for it?
4. can I also use songs from other manufacturers? E.g. from Dance Dance Revolution?

Many thanks in advance.

Regards R.Lehmeier