Bought this 18ga pneumatic from HF for $20 - http://www.harborfreight.com/18-gaug...ler-68019.html
Used 1/4" crown x 7/8" galvanized staples. 1" apart
I used unitized backing carpet left over from my pontoon referb. Due to me not skimping on the deck carpet quality, it is twice as thick as standard bunk carpet. Went on with no problems but the heavier carpet was more difficult to wrap, hold and staple.
Close up is of the carpet but also my 3 yr old "helping" and all the screws I retrieved from the tube