I have a humble 10in Altair Astro truss-tube RC (I think its a re-badged GSO…). So can’t help with dimensions but in general…
I am still ‘commisioning’ it properly but would say the first thing is to get a decent focuser. I now have a Starlight 3in Feathertouch with their ‘posidrive’ motorised add-on. I had hoopla with sourcing here, TS in Germany came good for me in the end. There are three moving parts in collimation which makes life ‘interesting’: focuser backplate, secondary, and primary. A Laser, Cheshire, and CCD inspector (respectively) all came in handy here.
It sits on a MESU 200 mount (friction drive). My AZEQ6 was not up to it…. I would guess a mount like the MESU or better would be required