Servos, I like to always get the biggest and best I can afford these days.
People seem to forget that just A couple of years ago, about 8 years ago, A 50oz/in servo was a big one. On big giant war birds and stunt planes we had to gang them together but these were big IMAA and IMAC planes. Today everyone is stuck on the big digital servo must have thinking. It just isn't so. Go by the weight of the plane and how you plan on flying it. There are some good sites with charts showing the type and weight of A plane and the servos required to fly it.
Today I installed some JR 8411 digital servos with 155 oz/in {4.8V} in A very old 60 size Bridi Kaos. I have flown this plane with servos from 48 oz/in and bigger for years. Why the big ones?? Just for fun, I just happened to have them and not being used for anything at the moment.
Pick the servos needed for the plane then if you have the money buy even better ones, they will be with you for years and have A lot of different uses over time.