Here is a good place to buy Power Poles. http://www.rothwellmarine.com/internetspecials.asp.
Very personable to deal with, fast free shipping also. They discount also.
Purdy 2011 Nitro Z9DC, Merc 250 Pro XS, Bob's Hydraulic, Bravo 1, Lowrance Gen 2 HDS 7, Gen 2 and Gen 3 12s, Twin 10'Power Pole Blades