I got these and they were the best servo s ever, Turnigy HV 306 from Hobby K around $24 ultra fast and smoothe. on special half price. I think theyre the micro size for all 450 size
Top tip. take off the skid pipe, and extend the arms with some training rods to about 4 inches then add on the same for the tail fin. giving you extra height will give you confidence. I actually heated up the plastic skid arms and spread them wider and bound on some training legs with fine cord or strong cotton , finish all over with some CA to hold it all tight. works real well for me. If you make this strong enough and brace it well then it will allow you to take a hard drop from hovering height without severe damage.
I did have a link showing this somewhere on one of my posts.
- - - Updated - - -
I have a Pro and a Sport 450 but ive had so much trouble with tail servos ive now got them bothe mounted on the tail, much easier to service etc. Then you can upgrade to a Futaba s9257 which I recon cant be beat for a 450. not cheap but well worth it. Ive had new Align tail servos that just stopped working with no obvious reason, my cyclic s done the same, now with those Turnigy 306 I have never had a moments trouble. I think they would do a tail servo too.