custom railroad uniform

Sounds like you have a couple of needs:

• Someone to design your RR logo, assuming it's not done already.  For that you'll need considerably more artistic skills than I possess - or know someone else who does.  If neither applies, you may want to consider using a service that creates logos for businesses - Google "company logo design" and check out the variety of options you have.
• Next, someone to make the clothing.  The trick is finding folks who do small runs and the best I've found is Lands' End Business (https://business.landsend.com/).  Once you pay to have the logo set up, they'll run individual items you can order from a large catalog of their clothing items.  I've used them for years in my own business and always been pleased by the results.

Good luck!

Probably your least expensive option will be to find a used original (your size) on eBay and go from there. Hats seem to be running around $100, with jackets running $200-300. I'd suggest starting with a $500 budget. If that's what you want, better start saving. Using a Tuxedo as an example, you'd be hard pressed to get a custom tailored one for less than $1K.

Any progress on a layout?

Work on the logo/herald - search for railroad heralds and find one that you the like the design of - borrow from it and sketch yours in colored pencil -

then you can make it happen -

That's a good uniform for modern railroaders - typical of what is worn today. 

Check with people/companies on Etsy and on teespring. They may be able to to custom runs/one off items.