I bought a Trek 7.3 FX and I had to test ride the 7.2 rather than the 7.3. The 7.2 the shop had in stock was the correct frame size for me. Plus, they had a smaller framed 7.3 so I got to touch and feel the actual bike before ordering it in my frame size. I was fine with that. However, the bike I actually wanted was the GT Tachyon Comp and the shop didn't have one in stock at all at any frame size. Ultimately, I went for the Trek 7.3 FX because purchasing a bike blindly was not something I am willing to do.

What I'm saying is - I understand your situation. It can be a tough call. I understand that the shops can't stock every bike in every size, but then again I have to be a responsible consumer. Weight that against the fact that the shop will want to sell you the bikes they have in stock... You got some thinking to do. :-)