Help with new project.

Hey I would like to discuss step by step (base, conversion needs, elecs, etc) A new project for a noob. I will try not to ask dumb questions.

First, my options. I am getting the money together, got most of it to get a new nitro vehicle for a conversion. My main choices are the Rc8 because I like it more than any other buggy for some reason and buggies are awesome. Some sort of truggy, like a kyosho inferno, the cheap one or a larger on road.
Also considering a crt.5 but would rather have the extra size. Trying to stay under 500$ with this part.

Second about mechanical brakes. In your own words ( very essay like)
why would you use mechanical brakes when the esc has braking function that you can tune?

I will ask about electronics once I decide what platform to start with because they will most likely greatly vary.

Please dont be shy. please help me out with your opinions and experiences.

Just remembered to ask. A muggy would be like an lst2 with center diff right? Elecs just went up to power something this big lol