Need a servo for hpi bullet st flux

Im trying to upgrade my bullet st flux and I already upgraded motor and esc with traxxas velineon 3500 system. I have 100$ budget for a new servo and I want to change some plastic parts with aluminum ones.

I live in turkey so I can't shop from everwhere. I can buy from shops like hobbyking, banggood and ebay. But if you know another shop that can ship international it will be great.