Sidekick to my Surface Pro?

https://sites.google.com/site/ovedivansite/surface-pro

So I have used my Surface Pro twice on the job and I feel I've beaten it up a bit. While i'm putting together diagrams its hot, i'm sweating all over it and in between roofs and walls it takes the occasional hit here and there. I don't only use it out there of course its main purpose is fulfilled at my desk when I have to edit pics and red mark documents. Do you all recommend a sidekick to my Surface Pro for drawing these surveys I do occasionally? With skydrive and one note if I were to use another tablet that would allow me to draw on it only i could sync my surveys and just open my surface pro at my desk and continue working. What do you all think?