So as long as I stay with a Rockshox fork with a 1 1/8" steerer tube I'll be ok, correct?

And the swap just includes the deassembling and reassembling of the bike, no extra parts needed?

I'm looking on Ebay and with every used fork I'm seeing "steerer tube cut to 7 1/4" or the like. I guess there's no standard length to cut the tube to, huh?