The Serpent GT is a great car! Good choice!
I really like savox servos in the bigger scales so long as you have a decent esc capable of putting out a good stable BEC. I used the Tekin RX8 Gen2 esc and T8 motors. That esc has the ability to run the BEC at 7.4v and so the brown out issues people talk about with savox servos is not an issue.
Other esc options include hobbywing however I think the Tekin is far superior.
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.