English Language A-level Persuasive Text.... HELP!!!!!!!!!!???????

Hi,
So I'm behind the rest of my class on choosing a topic because everybody else has already done it.. I'm thinking of controversial topics such as losing lad mags, or more ethical issues such as child brides, forced marriage etc.
At the moment, I think the one I feel most passionate about is the losing lad mags and the consequences to women because they provide a sense of normality to the sexualisation of women..
I want to make it a speech, but the criteria is to have a challenging audience, and therefore I'm not sure whether adopting the persona of a charity is 'challenging'? So basically
1.I need to adopt the persona of someone
2. and to know who the speech will be given to.
Please help with the above questions - IT MUST BE A CHALLENGING AUDIENCE
thanks!!!