SSCX Only!

Is an eccentric bb a better option than a chain tensioner?

I think that's open to debate. I've run both and I find the chain tensioner much simpler to use and maintain, especially as the EBB I had requires you to remove the nds crank to tension the chain. I do plan to get a better quality EBB and try again at some point over the summer. Some people claim that a chain tensioner isn't up to handling the torque you generate in cross, but I've never had that problem.

Any better options in steel?

A Pompino is the obvious choice. My first SSCX bike was one, and I enjoyed riding it off road a lot. The mud clearance wasn't great, but it was one of the earlier versions and On-One have improved that since. There does seem to be a lot more choice for specific SSCX steel frames though, i.e. All-City, Traitor, Genesis, Kona et al.