mmm,
The only thing is that i will most likely use the pier for 3 - 4 years max (and im in the middle of perth so it will be narrow band imgaing). the pier will be at floor height though i will be cutting the concrete and digging a 600 by 400 x 400 hole to drop the foundations into which will be seperate from the shed floor.
so as for size like paul suggests if i had a 200mm Square tube with say 10-12mm walls this should be 100% for what i need. Wind should not be a factor here as the obs will protect it a reasonable amount and if its blowing its A55 out your not going to get good images anyhow. Im expecting the pier height to be approximately 1.2m tall and I know my tube/accessories/guidescope is approximately 26kgs + the mount head (eq6)
I know i wont be upgrading my telescope for now because of the fact im a university student

and i purchased the bulk of the equipment when i was working fulltime... plus the minister of war and finance wouldn't approve such purchases without me having a full time job again

and that will occure when i move out of the house i am in at the moment

hence ill build a brand new obs with all the fandangled bits!