For the CRT.5, this is what I would choose for a limited budget:
Mamba Max (MM) ESC
Feigao 9L or Feigao 8L
Maxamps 3s 5000mah 20C Lipo
Castle Creations BEC
I realize that's pretty much what BrianG said, but it is a good setup.
SH Z-Car, Custom Crawler, 8s Savage,
12s XTM XLB 1/7 buggy,
4wd 4-link rear/IFS Pro4 truck,
Custom Hyper 10 Short Course,
Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz