Pre 78 = 77 Suzuki or Yamaha (in that order), and forget the rest unless you want to go hardcore on aftermarket bits.... The Suzuki apparently handles better, while the Yamaha goes better.
I can tell you that finding parts is no drama for the YZ-D (many interchangeable parts with E & F models along with ITs and DTs. 125E pipe helps, but I wouldn't describe it as as a must-do mod.
Evo =
Nobody seems to talk much about 'em, but I think it comes back to the 1980 YZ or RM (again). Be interested to hear other opinions on this.
Pre-85 = Honda or Kawasaki. I think the KX was the faster race bike, but if my experience in getting KDX parts is anything to go by, get the Honda.
Not Yamaha, 'cause the motor is a slug (relatively speaking).
Probably not Suzuki 'cause they forgot how to make decent MX motors in the mid-80s.
Definitely not the Husky (although Fernando's young fella is damn quick on his...).
The 84 KTMs break the front part of the engine off, but are supposed to be rocketships when they go (Dennis, hurry up and finsih yours so I can have a ride!).
And ignore Rosco...
If he's a racing newbie, he'll be better off on a little bike (for the short~medium term at least).
