If you are going offroad you could add a tyre repair kit.
I'd also take a couple of ratchet straps incase something breaks (like part of the tie-down system). Always useful.
However, the important thing once it arrives is to get out there and camp with it (before you run out of summer). That way you will learn quickly what you really need. Being you aren't in a 3rd world country you don't need to worry too much about predicting every possible item that might be required in advance. However, you could do a short one or two night camping trip somewhere local first so if you find you've forgotten something you can go back home for it.
Happy camping,
Steve.
