Would it be better for tax purposes to buy a shed for a home office and write the cost of purchase off, or rent to own and use the rent as a write off?

I'm looking into buying a shed to use as a home office so that I am not taking over the house anymore! Would it be a smarter business move to buy the shed out right and then claim it as a deduction on my taxes (including the installation) or rent to own it and then claiming the monthly rent as a tax deduction?? I currently just have two small businesses that don't make an exceptional amount of money so I don't know which one would work better when it comes to tax deductions it's all pretty new to me!