How to setup min order prices only on certain prodcuts

Hi all,

On my site, I want to have not only a min order vaue of £160, but i also want my customers to be able to order certain products without the min order value.

I could setup paypal to display when this min order value is reached, the only problem is that it would apply to all products.

The question is how would i set this up so that only certain products need a min order value?

Many thanks