Shipping Module for different shipping methods/costs/countries/

Hello,
I am trying to find the best way to setup the shipping in Zen cart (v1.51) but it does not meet my requirement. I have already red the different messages in this forum and installed different plugins.

I try to explain my need hoping that somebody is so kind to help me.

I have different items.
A B

Shipping costs:
for A - 5 for region 1 - 9 for region 2
for B - 9 for region 1 - 15 for region 2 - 6 for country X with carrier (AZ) - 20 for country K with carrier (AY)

If a customer in region 1 buys: A+B I want to cap the shipping costs to 9.
if a customer in region 2 buys 2A+3B I wanto co cap the shipping costs to 19.

It looks quite complicated (for me).

I tried to use the option perweightunit replacing the weight with the shipping cost but I cannot select the countries...

You help is very appreciated, many thanks in advance.

GG