Ok... If you are wanting to ask businesses to sponsor you. You should think in terms of why they should put thier products on you. What is in it for them? It isn't always about the skills. Lots of snow resort personel get gear tossed at them at no or little charge. Are they sponsored?
I would think that if you are asking for gear to be tossed to you, you should at a minimum explain why they should do that. It is a misconception that businesses will give you stuff just because you got skills. I doubt a representative is going to run up to you and say "Wow! awesome cork 9, you deserve a new board"! Sure, if you are winning comps left and right, eventually a rep is going to ask who are your sponsors?
Think of it as a job, submit a resume that reads like a portfolio. Pics, stats, comp results, personal data, video and a narrative on why you want to represent that company.
Chances are that you already have a huge sponsor, if you do more for them, I bet in return, they will do more for you.
Here is a portfolio that could easily be transformed into a request for sponsorship.
http://www.meaghanbuisson.com/portfolio_12Oct06.pdf
Good Luck