don't be afraid to have some cheep spares too, maybe blue birds just in case.
I run blue birds in my maxx and buggy, if you have a radio with EPA then they're great servos for the money, but if your radio dosen't have EPA then they might burm up.
the Spektrum/JR Z590M is a good cheap servo, you can get two spektrum 590 for $25 on ebay new.