Yes I got treated lumber, and have brought a tin of preservative to paint the ends after sawing. I shall make sure that the timber is only resting on brick - not earth so it should last as long as I need it to.
I am thinking about the conduit, but no final conclusion yet.
skybsd: how far south are you? I find that being in south London means that the view south is better light pollution wise than it would be if you were north of the river.
-------------------- Orion Optics UK 350mm Dob
Celestron 8SE
Bressier R-127L + minus violet filter(F=1200mm achromatic)
ETX125
Revelation 80mmED
W0 ZS66
EQ6 Pro
DSI I