How to set up different flat rates for items

Not sure how to do this. I need to set up a flat rate shipping for a pair of shoes at 16.00 and 3 dollars extra per pair sold. So, 1 pair shipping equals 16. 2 pair would be 16 plus 3 dollars for a total of 19 and so on.

But, I sell another product, a cleaning kit that the shipping will be 8 dollars for one kit and an extra 2 dollars for each additional kit.

So would I a set up flat rate with two different shipping classes? If so, how do I set the flat for the shoes at 16 with a 3 dollar quantity price of 3 dollars starting with the second pair?

Any help would be greatly appreciated.

Thanks!