Saddle stitching, 2 needles, like most people. I have a speedy stitcher and it can make a decent stitch, too (it's a lock stitch, by the way).
I prepunch my holes for saddle stitch and have not tried punching on the fly with an awl.
With the caveat that I'm only at this a couple of years, I just find stitching ponys fussy and inconvenient. Clamp the pony to the bench and the work into the pony and half the time, one of those things is going to move. Then you only get so many stitches before you have to shift the work. Projects like hats and holsters don't fit in them very well. I'm sure they do for somebody, but not for me. Knife sheaths, wallets, small stuff fits ok, but still fiddly.
I find it easier to hold whatever I'm working on in my hands either on a workbench or just in my lap.
Just my rookie outlook on stitching ponys. That said, a stitching pony is probably a good investment for most people who intend to saddle stitch.
On the subject of not overbuying, I'd refer you to a couple of recent threads by an experienced crafter, making nice pieces using a small set of beginner tools. There are so many tools and methods out there, it's just hard to know what to buy when you first start out.
https://leatherworker.net/forum/topic/125186-leather-projects-using-50-dollars-of-amazon-tools/
https://leatherworker.net/forum/topic/122892-back-at-tooling/
Practice - it's free except for the leather. Maybe grab a bag of scraps and practice sewing.
There's a "Getting Started" forum. It might be worth poking around over there and maybe ask for advice on a beginner tool set.