Requires a larger deposit but is simply your purchase price less the deposit divided by the number of repayments, with no interest or fees charged. You also benefit from the extra protection under the Consumer Credit Act 1974.
Requires a larger deposit and enables the products to be installed sooner rather than later. If settled within the deferred period, then no interest charges will be incurred. If not settled within the deferred period then interest will have accrued from the start of the contract and it will continue to be charged once you start your monthly payments.
Offers you the lowest initial outlay by way of deposit. Repayments are then flexible but subject to the minimum repayment. You can therefore control the term of the loan and the interest you would pay. You also benefit from the extra protection under the Consumer Credit Act 1974.