IF you do invest in a fully tooled out shop then jsut jump right in and start building from scratch. A kit guitar is for people who lack the tools and build guitars in their kitchen imho.
A drum sander is a wonderful machine but only if you plan on building a lot and learning how to use planes and scrapers is a good skill for many other things then just thinning backs and sides.
Investing in education can also be a good idea too if you want to go pro at this. Having school of 'such and such' luthiery on your 'about' page of your website carries a lot of weight and you might even learn something too
Some people are naturally talented at this sort of thing but most of us take a lot of practice. So I would not count on having a viable guitar for sale until you build at least ten. So jumping right in and learning by doing and making mistakes will get you there faster.