Thanks for the responses.
I think eventually moving to a limited company is the way to go, however I spoke to an accountant earlier and based on my estimated turnover of 3-4K from September to April, he recommended I start as a sole proprietor to keep costs down. I think keeping costs down is going to have to be a priority, since i'm building from nothing. I'm based in the UK, so one-member LLC's arn't an option - it's "sole trader" or "Limited Company" with nothing in-between.
In terms of liability, I may take out some insurance just to cover myself in case of lawsuits.