...then why not buy from the shop who's time you spent measuring you? FWIW, anything between a 54 and a 56 will work just fine, you just have to make a few adjustments to the saddle, stem, and handlebars. Ask them to look for a used bike (chuukosha) for you. I would suggest getting at least Shimano 105 (ichimarugo) groupset (compo), but really even Sora would be fine for a beginner unless you're an accomplished athlete.
I have six road bikes which are at least two too many, and would be happy to part with either of a couple for rock bottom prices (just want to thin the herd)--BUT, they are located in Hiroshima, and last I checked Black Cat type delivery to Tokyo and the environs is about Y20,000 for a complete bike. The bikes: (1) Pinarello Galileo, 53 c-c, 53 tt, Campagnolo mechanicals (mostly Centaur or better), Most Crankset, Campy Khamsin wheels, Michelin tires--all in at Y80,000, and (2) Orbea Euskaltel, 54 c-c, 55 tt, Campagnolo mechanicals, Campy Scirroco wheels--Y100,000. Both are aluminum frames with carbon seat stays and carbon forks, both are in excellent shape, and both worth much more if I parted them out. Both have a mixture of new and lightly used mechanicals, with used frames in excellent shape (no crashes). Pictures and more details for the asking. Eventually will post both in the classified section here, but first will post in some local outlets in my area.
I've got all kinds of bike and wheel boxes--and really, if anyone has a cheap(er) method that works, I 'd be happy to use it (i.e. buyer's choice regarding how to ship)--for a newbie, I would imagine a built bike would make the most sense, but of course I would be happy to partially or completely dismantle and ship frame in one box, wheels in another, at whatever it costs to ship.