You can use JR and HiTec servos with lots of other brands of receivers including Futaba. And that's good because the HiTec 225 is a standout. It's a better price too. Size, power and weight beat the closest Futaba offers in that type. And there are a number of other HiTecs that thump Futaba servos. And JR has a couple that are also standout servos. And they have those LHS deals with their "everyday" line of servos that're great values and good servos.

You can only use Futaba servos with Futaba receivers. And with Futaba extensions and Y cables.