Hi --- I think that you will get offered finance or hire purchase through the dealer where you purchase the machine more easily as you will become one of their customers, just haggle the price of the bike and the APR of the finance to get it as cheap as possible, making sure you don't get stung for their expensive payment protection or extended warranty this is not compulsory.
These extra insurances are often added to the finance and interest charged on the policies making the deal more expensive than at first thought, you can shop around seperately for much cheaper cover if you want it.