why wouldn't i be able to even do a good sounding two way? and yes, i am aware of the amount of displacement and requirement for huge drivers.
It's not that you're not capable, but there's a lot of factors in the design process that you would surely overlook for a first time build - you might think you're going big but instead you might already mess it up the moment you pick your drivers.
Get your feet wet with stuff that's already out there -
maybe build a pair of statements like Jinjuku did. I recommended the Zaph TMM in the other thread for you earlier and I think that will be a very good beginner speaker.
If, eventually you want to make your own designs, learn about everything that makes a good speaker, and start small. You didn't learn Quantum Physics in Elementary school, did you? Someday, you might be very capable. For now though, learn how to assemble a speaker, before you worry about DESIGNING one!
Even getting a 2-way to sound right means integrating the drivers well so that the transition from midbass to tweeter is smooth and natural. The more "ways" you add, the more complexity you are adding.
Think of a full range driver (1-way) as a bicycle.
Think of a 2-way as a 21-speed Mountain Bike with shock absorbers and brakes.
Think of a 2.5-way as that 21-speed mountain bike, with a motorized component to give it just a bit of boost.
Think of a 3-way as a motor scooter
Think of a 4-way as a ducati
Which of the above can you confidently say you can DESIGN and build from total scratch? Maybe the mountain bike, but not surely, right? Sure if you read up a bit more, you could surely design the mountain bike, even with the motor boost, but that doesn't mean you have so much experience that it would be foolproof.
Maybe first focus on learning how to build. With a schematic and all the parts in front of you you could assemble even the ducati while slowly learning what each part does and how it is supposed to go etc.