What an interesting topic!
I'm thinking that, as school fees are paid termly, you would need a lending product that perhaps draws down in stages? If repayments were calculated to cover the entire total drawdown, in the beginning, when only one or two terms funds had been drawn, you would benefit from making the same payment on the lower amount. I'm not explaining this very well, but do you see what I mean?
You could tailor a very specific product for this kind of borrowing, and with the education system the way it is currently, I am sure it would be a very popular product!
I have four children who benefit from the second-to-none Welsh medium education that is available in Wales. I am very thankful that, for me, this isn't an issue. But there must be thousands of parents out there, like you, who want to make the best effort they can on behalf of their children and thus I am surprised, now that I think about it, that I have not seen specifically tailored products for school fee lending.
Good luck with it all. If you do find a lender who can tailor a product for you, be sure to let us know.
Cat