Chris,
I am not sure what you are meaning exactly when you say 300 lf of cabinets, say uppers and lowers in a kitchen for example would be 20 ft on average so that would be about 15 kitchens. That is not a lot , so you wouldn’t need a lot of production equipment or people for that. However, you need to allow for growth/expansion and you have to decide if you are going to do all aspects of the kitchen.
For example if you build your own drawer boxes, you would likely offer a few different styles with the most expensive likely being a solid wood box with dovetail joints. What equipment do you require for this process. The wholesaler can drop off a lift of rough maple, you would need to joint it, plane it, sand it and then cut to lengths and then dovetail the ends, glue it, sand it and finish it. So what do you need? You need a forklift to unload the lift, a jointer, a planer, a widebelt sander, a miter saw or up cut saw with automatic feeder and fence, a dovetail machine, a drawer clamp machine or manual clamps, a spray booth c/w make up air and fire suppression. So for every machine listed you can buy a cheap off shore one or a super expensive European/American one. Or like others mentioned you can send your drawer order to ABC drawers and they will send you the boxes built and finished.
This is just a vague description, but all aspects of a cabinet job are similar.
There are lots of folks out there doing 15 kitchens a year with a panel saw, cabinet saw, jointer, planer, smaller or cheap edgebander, band saw, drum/widebelt sander, drill press, maybe a shaper, small dust collector, miter saw and all the electric hand tools that go with it, drills , jig saw, belt sander, router, random orbit sanders, etc.
A cnc would be a nice upgrade as it can do a lot of work for you, but also a larger investment.
Everyone has their techniques and likes so this list can vary quite a bit.
There is a difference as well between residential and commercial work.
Just a little fyi, Lots of great cabinet makers and smart business people on this site, so good luck.