any ideas on the best way to mount swivel seats from a conversion van

[sawyer]

I just got some nice seats for real cheap,that swivel 360 degrees and all of the other ecessary functions. I was wondering if anyone had any ideas on how to mount them in a 72 blazer. I know I have to cut it down height wise already so I was thinking of welding parallel (I think it's called this) C-channels and bolting the base to that, but that makes it a little tough to carpet. The base of the seat is basically a 6" diameter pipe attached to a 12" square baseplate It sort of looks like a squarer and flatter version of Frosty's or Lincoln's hats if that makes any sense. The baseplate has four holes and was bolted through the floor. But that I am pretty sure would not be strong enough. My interior is stripped so any ideas that will work. . .will work. Also there is a matching electric bench/bed that is in perfect condition for only $15. I think it's a little lame but my friends seem to think it would be pretty cool. Any thoughts?