steering servo help

[crayon]

Hi guys i`ve just bought myself a new 1/10 4 wheel drive buggy for racing but i need a new steering servo, i`ve only normaly used standard one but did upgrade to a fast one in my 1/18 shark.
I have no idea what makes or speeds are out there i`m just after a cheap fastish servo,
If you could help with model numbers so i can have a look out for them, thanks Jamie