What I need:
Simply speaking, I need to turn my ‘cart’ page from this:

http://yfrog.com/0nsavouriescartpage420201p

into this: 

http://yfrog.com/jdfoodziecartpage42020105p

(I just want to change the way the shipping costs are presented, I don't care about the style or CSS right now).

I also want to change the shipping tab of my checkout page from this:

http://yfrog.com/3wsavouriescheckoutpageshp

to this:

http://yfrog.com/j9foodziecheckoutpageshipp

I would like it in the form of a custom module so we don’t have to change anything within the existing module.


Situation:

I already have Ubercart, uc_marketplace and the canadapost shipping modules set up.

How it calculates shipping right now is that it takes the marketplace host’s address and calculates shipping cost for all the products based on that. 

I don’t want that though. 

What I want is for it to group all the products belonging to their respective sellers together and calculate a shipping cost for each group based on the seller’s address. 

The shipping costs do not necessarily have to be displayed on the cart page. It should be displayed on the shipping tab of the checkout page though.

Extra:

 The uc_marketplace module has already incorporated a similar function for USPS and flatrate shipping.  You can find a lot of information in files for that module that you maybe able to apply to Canadapost.

Each product already has their only address field (where shipping cost calculation can be based on), you just need to customize it so that the shipping module reads those addresses rather than my address (as the marketplace host) and modify the way the shipping results are displayed. 

In other words, all the basics are in place. Things just need to be re-wired.

 
If you are interested in working on this, please let me know approximately how long this project will take you. Contact me for more information.

Thanks.

Jonathan