[DrKnow65]

I don't run 1/8th brushless yet but I'll try to put out what I think are the basics after having followed some of the threads here on buggy conversions.

How expensive= how high end (read reliable)

40MPH can be calculated on BrianG's speed calculator, you'll need to know gear ratio's tire sizes and other hard to find info, but once you have the info it's simple.

Pinion gear is both speed and load related, seems most "non racing" guys go for the best speed without overheating components. Load=heat

25 minutes will be dictated by the watts the motor is using vs. Mah of the lipo's. There is a thread here titled "what are your run times?" you could thumb through this thread to get general ideas for buggies similar to what you want to do.

Mechanical brake are the preferred method for 1/8th buggies as this keeps the load of braking off the motor. As I understand it you just "Y" the throttle cable and run one to the brake servo and the other to the ESC, there is something about turning off the brakes on the ESC (sorry, that means Electronic Speed Controller if you didn't know), I'm sure turning off the brakes will be dictated by whatever ESC you choose.

You can choose from a few brands of motor, Neu seem to be the best, Hacker is good to, Lehner is midrange, and Feigao is budget but acceptable.

ESC's seem to be a personal preference, some cooling mod's need to be done on certain ESC's... seems like Quark is the go-to but I'm not running HV (high voltage) so I'd go with whats popular. Mabey take note of what other buggies are using when you look at the run times thread.

Lipo's are another wide variety item. I've been wanting to step up to some Flightpower EVO30's as they look good and people say they use quality cells. MaxAmps has done me extremely well and their service rocks! (p.s. if you go MaxAmps use their 5000Mah packs)

So there, I've stirred the pot for you and others should be along to correct me shortly, that will net you some more info :) Good luck, welcome to the hobby, welcome to the forum. You will be tossing nitro motors in the trash pretty quick once you use brushless with lipo's.