According to the LeMond method, if your inseam is really 37.375, the calculation is 65% of that or a 61cm bike. I think a bike of 64cm like you are looking at is way too big. Because you are "all legs" you'll want a shorter top tube than normal.
I'd forget Motobecane and stick with a Trek or Specialized. They are the two biggest brands and make good bikes. If this is your first bike and you might get hooked then you'll probably want to sell it and selling a Trek or a Specialized is much easier than an off brand.
Since we don't know your budget or if you want a hybrid or a road bike here are some suggestions:
Trek 2.1, $1400 ==>
http://www.trekbikes.com/us/en/bikes/road/2_series/21/
Trek 1.2, $850 ==>
http://www.trekbikes.com/us/en/bikes/road/1_series/12/
Get out and ride some bikes. You'll quickly realize what works for you. You might try to rent some bikes too, lots of shops rent them, so you can get a sense of what size feels good on you.
Good luck
Bob
The Lemond method seems to be a bit off. I'm 6'5", 33" inseam and ride a 61cm Motobecane CF frame. Fits me perfectly. He's going to have to go a bit bigger on the frame to get a decent seatpost height, then swap out the stem for a shorter one. Probably a 64cm or 65cm. I built it up Motobecane using the components I wanted. It was a great deal on a cf frame.
People dis BD all the time, but they build nice bikes at a great price, There are lots of trolls that get hung up on the advertising and the fact that they bought some classic brands and put them back on the market. None of that changes the quality.