I think I have 1 to 2 inches.

I ride a 58cm. I think that I could have probably gone with a 56cm.

IMO, it's better to go with smaller than larger. I had to shorten my stem by 2cm and am stll pretty stretched out.

another reason to go smaller is that the frame will be lighter.

what bike did you say you are looking at?

Mr. has a 49cm Lemond Reno. If the bike that you are looking at, the smallest is 51c, then i would look at other bikes rather than try to fit onto a too large bike.