A GPS was handy for some of the trips we did. Not strictly necessary, but often the maps are very large scale so it can be handy. While you can use a smartphone, having a dedicated device was good, especially one you can change batteries in. I use a Garmin G2. If you do get one, consider subscribing to their satellite imagery it can be useful when the maps & tracks really don't exist. For most places you can get Open Street Map data in GPX format for free. Just Google for it, or this was one site I used a bit.
For cooking, we used a whisperlite international. It's good to have the international version as finding white fuel can be hard. The international will burn petrol, kerosene etc. In retrospect I think I would have got the MSR Dragonfly International now, but the whisperlite was fine. There's a handy link of white fuel transaltions here if you get stuck.
We got Primus ETA pots. I got the 1L and the 1.7L pots. They stack together, they have a heat exchange system so use significantly less fuel, boil in minutes on the MSR, are non-stick and have a built in strainer (should you need it). Very happy we bought them.