You can put the Ruby controller just about anywhere inside the plane. It can be flat or on its side. We prefer to simply put it in the payload area behind the battery. Just be sure that the controller's axes are level with the plane's axes. You'll probably have to insert some kind of shim to be sure that it's level.
If your payload area is already filled with battery and FPV electronics, you might dig out a chamber for Ruby in the hollow section behind the payload area.
Airspeed / Magnetometer
While it's possible to put the airspeed/magnetometer along with the controller inside the payload area and embed the pitot tubing in the nose, we find it best to embed this sensor in the bottom of the wing, about halfway out to the tip, at least a few inches away from the aileron servo. This avoids the battery from ramming against the sensor, avoids electromagnetic fields from the power lines, and possible ferrous or magnetic parts in the payload. It's also easier to align the magnetometer with the plane's flying axis when it's on the bottom of the wing.
Contact email@example.com if you'd like a cable extension that makes it easier to connect and disconnect the airspeed / magnetometer when attaching and removing the wing.
We prefer to embed the GPS in a pocket made on the top of the tail boom, or embedded entirely inside the tail boom as shown above. This gives best reception, gets it away from video transmitter, reduces clutter in the payload area, and helps to counter-balance extra FPV gear you might put in the payload area. Ideally, you can run the cabling forward to the payload area before gluing the two halves together, but you can also just create a slit for the cable on the outside of the finished fuselage.
You can also put the GPS above the wing, or on top of canopy or nose. We prefer to dig out a cavity in the foam for the GPS so it can be mounted flush /streamlined with the airframe skin.
When using satellite receivers, we like to embed them in the tail boom or vertical stabilizer, preferably prior to gluing the two fuselage halves together. This gives best reception, gets the receiver away from video transmitter, and reduces clutter. If you use two satellites, be sure to orient the antennae at 90 degrees to each other for best coverage.
When using larger / long range receivers such as the Dragonlink, we like to embed in the hollow section behind the payload area, preferably before gluing the two fuselage halves together. For best range, the antenna should be mounted vertically if possible. When the antenna comes at the end of a length of coax cable, it can be embedded in the vertical stabilizer.
Simply connect servos to Ruby as they are labeled on Ruby. Right aileron goes to "2 Ail R", etc... Note that the servo numbering on Ruby doesn't correspond to your transmitter / receiver channel numbers.