When you get the receiver pack, make sure it's a flat pack and while at your LHS make sure you get the switch that allows you to charge the pack without having to unplug the switch. The LHS should steer you the irght way and make sure the connectors are compatible. The most common connector types are the Futaba J connectors. As Jon said, most servos will fit, and sometimes a slight trim is needed to make them fit.
I had to do this with my JR receiver. My Futaba servo's needed the tabs trimmed off in order for them to plug right in.