I'm a hydraulic noob too, so value any of my advice commensurate with what you paid for it.
For a grapple, you'll probably want a "3rd Function" control mounted on the FEL joystick. So that's one complete circuit and set of parts/controls.
For rear remotes, the widely acknowledged "necessity" is a top and tilt pair of rear cylinders, which will require one control valve each, usually stacked. The "top" cylinder replaces your top link; the "tilt" cylinder replaces one of your side/lift arm links. Get valves that have a float/detent if possible so that you have the capability to lock them in the "on" position for some other rear implement that requires constant flow (like a splitter). If you're adding two rear remotes, it is usually not a lot more $ to just get 3. Less $ and hassle than if you later decide you need to add a 3rd. Your backhoe should mean that the tractor already comes equipped with either PTO-powered hydraulics for the hoe, or at least one rear remote circuit.
You'll usually spend a lot less if you can buy all your accessory hydraulics as a "package" from the dealer at the time of original sale. That said, you'll usually spend a lot MORE for factory/OEM parts than for aftermarket stuff. But the factory stuff will generally fit and will integrate in with your tractor best. If resale value is important to you, factory, integrated setups will likely command a premium.
