The best thing to do is find a bike shop that does something like RETUL fitting or similar. And have them take some measurement and they will be able to tell you what size bike to get depending on the make and style you want. Because even though you might have the same inseam, your arms might be longer etc. For example i am 5/11.5 with a 35 inseam, there this guy at the bike shop who is 6/2 and my arms are longer than his, RETUL put me on a 58cm frame. Its very important that your bike fits perfect for a number of reasons like power, efficiency, comfort, lower the risk of injures etc. i ride my CAAD10 and superSix 100mi with no discomfort what so ever, I paid $250 for a RETUL fit and it was well worth it.