Hi, Jonathan. The ambiance is not really hard to replicate. It's a low drone and there is a lot of stuff which make things easier in order to achieve results.
However, making the chase involves more resources, knowledge and a bit of musical theory (accents, complex, arpeggios over modes, inversions, and so on).
In my opinion is better to let a composer approach the soundtrack than try to do yourself all the sound job from scratch. At the end he or she will have the tools, equipment and the experience in that specific field. I think there's plenty of musicians in the community which can help you.
Cheers!