35s or 37s? And which hydro boost? Wild horses or Jame Duff?

[Broncobowsher]

While the HB is a good addition for larger tires, you need to find the root cause of your poor brakes first before adding anything else to the mix.

Hydroboost is a brake amplifier. Vacuum is as well, but hydroboost is better.
The thing is an amplifier doesn't care what it is amplifying. If you have a problem without hydroboost, you will have a bigger problem with hydroboost. It make good brakes really good. It makes small brake problem into big problems just the same.

Hydroboost doesn't add capacity. If you can fade the brakes without hydroboost, they will fade even faster with hydroboost. Friction surfaces, heat generation and heat soak stay the same. But it is so much easier to push into those limits.

Putting on larger tires is very much like putting on smaller brakes. The ratio of tire size to brake size matters.