Any high-end custom armorer worth their salt should be able to make one, but I urge you to take a step back and really spend a lot of time immersed in the artwork, survivals and consider getting Dr. Capwell's new book before jumping into commissioning anything you're going to spend several thousand dollars on. There is a lot of new information emerging right now about this very type of harness, it's not something you want to drop $12,000 on to find out 6 months from now it's all wrong because of information in Toby's research specific to the English style
Again, I'm not trying to discourage you and I'm thrilled with your enthusiasm, I'm just urging a cautious approach. You've got the budget to do things right. In order to pull it off with something that you're going to happy with for the rest of your life, I'd highly highly recommend that you spend a couple months really studying the sources and getting very intimate with the research before placing orders for anything.
You will always learn more over time and realize you could have made a slightly better decision at some point, some of that is inevitable, but take it from me and probably everyone else here, we've all probably wish we spent a little more time in the beginning and ended up having to buy a lot of things over again because we bought things too quickly.
