I've gotten nice linen thread from The Quartermaster General but it is in small spools like what is sold for sewing fabric. I do really like the Carriage brand of hemp thread from Tandy. It isn't cheap but it is very strong and very smooth compared to usual hemp "thread," it is finished much more like regular linen thread.
I now get my needles from Weaver leather, as well as having gotten their very handy (pun untended) stitching clam.
save facebook pictures to phoneWhile not 100% essential, it does make things a lot easier.
I usually don't mount it to anything, I just sit on the end of the long base.
A couple notes on some things others have mentioned.
If you are going to get a diamond awl from Tandy, get the series with the black handle, much better quality. There are better awls out there, and many different type for different purposes, but these get expensive quick.
Yes, the Tandy awl is very, very , sharp. But, you need to keep it that way, and do so without loosing the shape. Which is another good reason to not buy the most expensive awl right away, why mess that up learning to sharpen your awl. I touch mine up every time I start a line of stitching, and with certain leathers if the run is long might polish it a bit in process.
Avoid those "lock stitch" "stitching awls." Not sure why they call it a "lock stitch" because if you cut one stitch nothing is stopping it from unraveling.
I recently had to pull a line of stitch that I had worked very hard to do a proper saddle stitch on,,, what a pain it was to pull that apart.
I know the "poke and stitch" 2 needle method sounds intimidating and tedious, but, it is worth it and not so bad once you get going with it. And, you will be much happier with your finished work.
I forgot to mention it in my 1st post. Along with Capgun's topic series, get yourself a copy of Al Stohlman's book,