RE: Which servo should I get for my Hellfire??!
I run a Futaba 9351 in my Hellfire and I love it. I also have Hitec 5955's and JR 9000T and 9000S servos in other vehicles and I love them too.
Try your best not to cheap out on servos. If you don't want to around $100 or more, you could get by with a JR 650 though.