I think for most people, turning to a Johnson (or any other repro maker) for a fashion jacket isn't going to turn out very well. There's nobody to provide the taste/design required, much less spec-ing. If you want reprowear type stuff it's a good option, but most posters here are not capable of producing something good on their own.
I would agree about Johnson. I think that to work with him, unless there is already a body that fits you well, that you could end up with a few issues before getting things right. That said, he has worked with a lot of fashion companies, and so he does have those patterns, and can probably build you something off of those (though he is probably not allowed to use those patterns exactly. Johnson's is not a "repro" nor a "motorcycle" jacket maker, though. He really is a manufacturer.
A company like Aero, like I said, is completely different. It really is a fashion company - one focused on historical jackets. The good thing about this is that they have something for pretty much any fit you want, since we've gone through every fit in the past 100 years or so. 1930s jackets are as slim as pretty much any fashion jacket found in 2015, and 1960s were not dissimilar. On the other hand, there are plenty of other bodies that are a lot roomier. You can pretty easily put together something that could have been made by Junya, or Margiela, or Dior, based on your leather choices (in fact, the lighter leathers are less expensive), the trims you choose, etc...
There are, of course, brands that focus solely on repros, and of course, with those, you get what was advertised.