No one of them seem to give EVERY bit of knowledge, but visiting all three gives you a chance on scooping up everything needed to calculate kinetic energy, static load, dynamic capacity, torque capacity, other issues for operation, then how to select cylinders, park brake valves, design pedals, etc.
Then revisit the plans on this. I do not know if the Sonex plans are any good, but most folks that have been in homebuilts as long as these guys have pretty good direction on everything mechanical. Come back here with more specific questions...
I used the information from Matco site and picked out the wheels and brakes and then called and talked to the engineer/owner and after he asked all the questions, agreed on my pick. Also has good information on designing the ratio of the arm for the master cylinders for the toe brakes.
If you want to take a chance on getting to much brakes or not enough brakes and want to buy twice and take the chance of putting your tail dragger over on its nose or back with a prop strike, just guess.
So you go to the airport and look at a Piper Super Cub with dual Clevelands and it happens to have a set of 850 x 6" tires. Put the duel brakes on your Baby Ace or Cessna 140, etc. Both are very light on its tail and easy to over brake and end up with a bad day.
My daughter wanted the axle extenders on her Cessna 140 removed. The extenders moves the wheel axle forward 2". After removing you better have a light foot on the toe brakes.
On a tri-gear, it's a little more forgiving, to much brakes and the tires will slide and have a short life and to little, maybe run into another airplane on the ramp, or not get stopped at the end of the runway, etc. An Ercoupe with the old Goodyear brakes is a good example of not enough brakes.
wsimpso1 is correct. If you want to be happy with your brake selection, there is a lot to consider. Its up to you.
Back to your question. The complete braking system is a complete package. Just like everything else on the airplane, change one thing and it affects everything else.
And getting the geometry right of the toe brake master cylinders is important for getting the correct hydraulic fluid pressure for the brakes you are using.
Here is a link to information on the subject from Matco. Look around at there website for a lot of good information.