Are you looking for ease of fabrication in the first place, or ease of positioning/re-positioning equipment later?
By going with stainless, you've lost the former. 80/20 is made out of aluminum (with steel inserts and hardware) so it's easy to cut, drill etc. But even in aluminum it's FAR from inexpensive, even considering fabrication labour. I'd hate to imagine what 80/20 would be like in stainless- you'd need to sell body parts to pay for it!
If the latter is what you need, stainless UniStrut is probably the best you're going to get- the options are limited.