you can take Marcruger and Big Smoke posts to the bank. You are not glued to any specific choice of leather, and most of us have worked with leather at one time or another used everything from seconds and splits picked up at Rendezvous all the way through Weaver, Tandy and the vendors mentioned here.
Don't rush
Look around and dig up everything from Madison Grants book on the Kentucky Rifle Hunting Pouch, through the websites such as Track of The Wolf, , October Country, Springfield Leather, Crazy Crow, Wnadering Bull and all the others when you do a search.
Look through all the pages in this topic. You're not gonna believe what some of these guys have cranked out and your bag will be better for it.
Be frugal when you start buying tools on top of what you already have.
There's a series in here entitled Every Man A Cobbler by some crackpot which is by no means the end all, but it might give you some ideas on where to start and how to work.
Have some fun, don't force anything and share your work with the rest of these coyotes who post in this section.
Godspeed
The Capgun Kid