Buggy = 8ight, Xray EC, Kyosho or Mugen. Honestly if I were you it would be Mugen because that is where you came from. You will love the new car.
Get light screws and run Lipo in it to reduce the weight! You will need a regulator.
Motor = Novarossi, RB. Just depends on the size of the track.
Pipe = .053, .086 or JP-3 based on the track
Servos = Futaba or Ace. Get coreless motors. Futaba has brushless servos coming out that will be the end all for servos.
Radio = Futaba, KO or M-11. I love my M-11 and again it will be something you are more familiar with. Spectrum has a cool radio right around the corner.
I love the 2.4ghz stuff.
Money is no object??? Buy the matching truggy! It will give you something else to do. Buy a big motor and laugh your a$$ off. You paid for it!