You really have a lot of options there once you work out your total payload.
Options are Steel, timber or Carbon fibre depending on any other uses.
I ended going carbon fibre just because I wanted it for my larger scope & dm6 mount/ camera and small scope for terestrial use. (Strong multi use and light weight)
I keep the leg segments open to only 2 when using for Astro use but has the extra length for terrestrial use.
Went with a gitzo Gt5532Ls
Good luck with your choice
