Looking for advice on sewing machine thread

[Øye]

I recently acquired this machine and got it back from the repair shop, and was looking for any pointers on good thread to use on leather. I've been sewing for a long time, but only cloth with a machine. I'm looking for a heavier thread that will still run smoothly.

 

[Horsewright]

Might try here:

https://www.leathermachineco.com/products/needles-thread/