It will work for bukkit too... when cpw finishes what he's doing on the mcpc side.
Make sure both client and server versions of forge are the same.
Make sure you aren't doing anything silly too, like using a snapshot server or client.
Simply put, until the next mystcraft is released, use the version of forge they need.
And I'm sorry, but you'll need to use an older railcraft version.
I'm using 299 with optifine and it works. sp614x usually only updates when forge compatibility is broken for some reason.
And speaking of jenkins being down, it's been like that for 3 days already.