Requirements: Digital, lower than .10sec/60*, over 80oz-in. Any servo meeting that criteria will be ideal for your car. Airtronics 94758 would be a good choice, or KO 2413.
What I use though, since I'm really cheap is a Hitec 5245MG. It has really good specs for a 10th buggy, its really light, small, and plus its way cheaper than your average standard size servo (only $44 at tower). I've been running it for 4 months now, and it is holding up really well.