Wordpress Shipping Options, Edit Theme

I have an eCommerce theme which I need edited. The theme is http://shopperpress.com/ and I need to add more shipping options under the weight based system.

Currently the weight based system works by entering all the price details for the default country. I need to be able to enter different shipping costs based on weight for each country. ( Not based on the default country )

Example

5 KG post in Ireland = 5 euros
10 KG post in Ireland = 10 euros
15 KG post in Ireland = 15 euros

5KG in UK = 12 euros
10 KG in UK = 36 euros
15 KG in uk = 40 euros

Note: Price per KG is not a set amound and can change from country to country.