Yeah the Stewmac stuff can be hideously expensive, but a lot of it is designed with 'pro' guitar builders/repairers in mind. Plenty of other ways to achieve the same results, but if you're doing it for a living time is money. My old mentor would've loved a lot of the catalogue when he set out 50 odd years ago but it just didn't exist.I think the answers have been given in good faith here. I have gotten few planes that are in use, but one came from a luthier half a decade ago or more - it was a 15 inch panel plane. Probably the only plane he was using.
I understand almost everyone making acoustics now uses a drum sander, and depending on how serious you get, you may wish to aim for stiffness instead of thickness on a top and have a need to make adjustments.
I haven't made an acoustic yet, but have trimmed 1/8th, 1/10th solid wood to thickness and it's definitely not quite as easy thicknessing something from solid. The risk of making the stock too thin in the center is much greater - you'd probably not mind making yourself some kind of scraper if you want to hand thickness those tops so that you can work slowly and safely on something that can definitely be planed by hand, but can get hairy with the cap iron set on a plane due to the tension needed to hold the workpiece in place.
I don't think I mentioned it earlier - maybe I did. A *really* good 24" reference steel straight edge is nice to have. these used to be about $55 here shipped (starrett 24" 380). With a good straight edge, you can make a million other custom use tools, like long "sanding bars" or blocks, etc, and avoid having to buy less accurate extruded aluminum stuff that adds up.
And on the stew mac-ish stuff, I'd go light on most of those kinds of things until you have a need. I *would* spend money on something that will cleanly cut the binding channel, but just basic. You'll get the skill to be able to wing it some of things more complicated. For example, stew mac sells some kind of solution to cut a binding channel on a carved top - it is insane ($453 with bits and *no* trim router). I've been using a router bit in a cordless die grinder with a stop clamped to the side.
I've cut that binding channel by hand, too, which is doable. Perhaps stew mac's solution takes about 1 minute to cut a binding channel.
Cutting one by hand cleanly can be really long on a guitar with a combination of hard and soft woods - like an hour or three depending, and it's brutally careful work.
And the cordless die grinder solution takes about 2 minutes, and isn't as risky to use as it sounds.
There will be a million small decisions like that.
I'll never regret the starrett edge, though they have doubled at this point.
I've bought a lot of SM tools especially during lockdown as I intend to make Luthiery my retirement job.