Octave A's

I recently sold my 6-string that had octave A's (in opposed to unison) and liked its deeper sound when strummed. I now have an 8-string, and would like to try-it-out on this instrument. I've never seen it done on an 8-string, has anyone?
Part 2: Rather than try to track down a low A, do you think I could get away with just using a Low G and tuning it up to A? I can't imagine there is much difference between the two anyway... or is there?

The low G tuned up a whole step should probably be fine. Just make sure it'll fit in the nut. Never saw that stringing for an 8-string before, but I like the octave A sound too so I'd probably do it if I had an 8-string.

I like the octave A too. DOn't have an 8-string, though I did once, but I would go for it with the low G tuned up a step as you suggest.