Went to two local LBS's to get fit. Both came up with the same numbers: I need a 56 seat tube and a 52 top tube (assuming a 10 cm stem). I've been riding a 56 x 56 lugged steel frame with a 10 cm stem and feel a little too stretched out. Anyways, is it advisable to take my frame to an expert and get the top and down tubes altered to come up with a 52 top tube? Would it be about the same cost to just get a custom frame built? Thanks.