Tekin rx8 gen2 should be your primary choice. It is a much better esc than castle. I've had both and the Tekin is far smoother, more tunable and has the ability to run 7.4v BEC so you can use HV servos which is really handy in 1/8th cars.
Serpent Viper 977e, Serpent Project 4x, Serpent 811T-TE Truggy, Serpent 811e 2.1, Serpent 411 4.0 Eryx, Serpent SRX-2 RM, Serpent SRX-4, Serpent F110-SF2, Serpent F180, Serpent 748 Natrix WC, Serpent Cobra GT 3.0, Serpent SRX8, Serpent S811 2.2, Baja 5B Flux, Atomic AMZ 1/27th, Schumacher GT12 SS.
Sanwa, Ielasi Tuned Novarossi Racing Engines, Tekin, Hobbywing, Muchmore.