Decks, Patios, Porches and Docks - building a pipe dock

I am going to build a pipe dock on a small lake and am looking to tie a 16' boat with a 70hp to it. The water varies about 2 feet during the summer with normal small lake wave activity and I plan on taking it out over the winter. The slope is gradual, fom beach to 8 feet deep is about a 20" run. the bottom is gravel and rock.
My questions are:
will a 4 foot wide dock be stable enough for my purpose?
what type of poles are recommended (is there a cheaper home depot type alternative to the specialty hardware)?
do you use bases or just let the pipes sink as much as possible?

any links to plans?

thanks!

At my parent's cottage, the usual dock setup uses stands that are basicly pipes welded together or something, there's a plate at the bottom (because otherwise the pipe would just keep sinking further in over time)

This link to a setup available on e-bay shows something similar:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4550494923&category=26451

has anybody built a pipe dock? will it be able to hold a 16' boat in moderate (6"-8") waves?

Can somebody point me to a dock forum?

I don't know of any forums but heres a book you might check out.

http://www.amazon.com/exec/obidos/tg/detail/-/1580170986/102-6569887-0859317?v=glance