I dunno. I'm also long of leg/shorter torso, (albeit a lot shorter) and my cycling life was changed by realizing I needed to size down to find the right fit. I'm 5'9" with a 33" inseam, and everything and everyone on the planet puts me on a 54, but the first time I got on a 52, it was obviously perfect. (I had a 54 that I put a short stem on and the handling got twitchy. The 52 was night and day compared to that. I got rid of it and got the 52.)
my my point is, don't be so sure the 61 is the right size. I think it might be better to get the 58 and then put a longer stem on it if you needed more reach. If an average person 6'4" is "supposed" to ride a 61, I'd pick the 58.