anyone tell me anything about these.  they look pretty cool.  i'm sure their an arm and a leg as far as pricing goes.  do they even come as semi's or just smg?

They're only available in SMG form - no semis.  And with the exception of a couple Mpi69's, all of them are dealer samples (pre or post).  The Mpi81 is basicly an updated Mpi69 - very few changes between the two guns.  I think the main change was the switch from a cocking knob to a strap (or vice-versa... I can't remember).  If you want a SMG, you may as well get an Uzi - they are very similar in appearance and when shooting, they feel quite similar to one.