I think you can use a standard shielded network cable for a mike 
extension.  Worse case, you might have to put a choke on it.  I've read of 
other folks using cat five extensions for this with no problems.
I really would never consider the 200 watt version, takes more power, only 
gains you 3 db, and one more thing to go wrong.  The only real complaint I 
have with this radio is Kenwood went to a smaller power connecter, so old 
power cords won't work.  I wish someone made a pig tail adapter for this.
73s
Butch Bussen
wa0vjr