Here's a place you can get smaller amounts of tiger thread:
https://www.etsy.com/listing/173847749/08mm-tiger-thread?ref=shop_home_active_1
That said, I get mine from Ludlow Leather, and it's no more expensive than the cheap tandy stuff. It's ten dollars more, but there's more of it. And it's amazing to use!
I use a pricking iron and go all the way around in advance. I have sewed two pieces of 9 oz together in this fashion. Lots of counting holes, though.
When I first started, I used a round awl or a drill bit to make holes, in an attempt to not have to buy so many tools, but they would tear a little bit as you sewed. The diamond shape works really well.