Multiple Location Shipping

I have multiple warehouses where i ship my items from.
the visitor could for example add an item to their cart from warehouse 1 and two items from warehouse 2.
In addition, warehouse 1 could have different pricing table for shipping from other warehouses.

So, what will be the easiest way to do this?, is there already an add-on for this type of multi-location shipping?

Easiest way would be to give each product its own shipping cost. I have a module for that called shipping by product

hmm, but then the combine shipping option would be disabled, what if someone adds 50qty of one item, i would like them to get a discount, since its being shipped from one location

or even if they add:
50qty of item1 (located in warehouse1)
50qty of item2 (located in warehouse2)
it would be nice to still give them a combined price based on shipping weight for all the items combined comming from the one warehouse?

could your Shipping By Product somehow be used for multiple shipping methods selection? i.e. Standard, Fast, Express ?

Shipping By product supports ranges per item
So you can have 1@$5.00, 2@$2.00(ea), 3@1.00(ea) etc