Anyone know what kind of choke tube its a Valmet 412. Also where can I get some steel choke tubes.

Check with Trulock Chokes. http://trulockchokes.com/chokesearch.asp
Most of their tubes are rated for steel shot.

I've been using a set of the extended tubes in my Fausti O/U for several years to shoot sporting clays. They seem to be good quality.