Museum Replicas Limited (MRL) also produced a Strider coat. Although they have discontinued their LOTR line, you could probably still find a reseller on-line that has it in-stock.
I own one of these and thought it was pretty close for accuracy... all leather, real stiching, no zippers or pockets. Even if you wanted to make some modifications, it might be easier to start with this as your base coat, unless you have e xp erience making clothing from leather (and have a pattern to follow).
I also own the Davis Anderson version. I know, why do I own two coats? I knew they were becoming "extinct" and I couldn't decide, so I bought both. Once I had them, I couldn't decide which to return, so I just kept them both. Even owning both it is hard to pick which is better. They each have their pros and cons.
The Davis Anderson version is pretty scarce at this point I believe. At first look, it is pretty accurate; however, I hate that the arm stiching and around the waist isn't really stiching. The lining, zippers, pockets, etc make for a comfortable wearable coat, but not quite as movie-accurate in that way as the MRL version. Really depends what you are going for.
Haven't seen the Kropserkel version in person, but their stuff is always top-notch. You could always buy one of those and then post a nice review of it for the rest of us. I doubt you would be disappointed in their work, but it will cost you.
btw, here is a pic of my aragorn costume a couple of years ago. 
