MH Purity:
This theme is quite nice and simple which means I'd be able to apply my own styling to it very easily. It has fairly basic features but I think I'd be able to bring in pretty much everything I need using plug-ins.
Tracks:
This is another clean and simple theme but it seems more centred towards blog post style layout so it would mean more work to change to what I need.
Adventurous:
This theme has a nice full page slider, something that I'd definitely like to include to display things further up in the information hierarchy.
After considering all my options I think I'm going to use the MH Purity theme, I think it allows for the most flexibility and adaptability while still providing a solid underlying base for my site.