Hi Robin,
I did the pier in the backyard job and love to use it as often as I can but make it as strong as you think is needed and then make it stronger because its easier to do it once then try and and make it stronger down the track.
heres a link to the one I put in
http://www.iceinspace.com.au/forum/s...t=30434&page=2
And now I have added a heq5 pro mount to the top of it and its still rock soild.
Just a option for you to think about.