Shipping related Customization.

I am working on NopCommerce Customization. Just now I moved on the Shipping module. And I saw I need to customize it. My requirements are as below.

I want to ship products only in Australia. For that I have condition that I can ship below or equal to 20kg and less then 105cm long. If this condition is satisfied the Australian Post is there for to ship them but if exceeds I have use direct freight shipping.

In Direct Freight,

The maximum allowable weight per Item is 25kg. If weight is greater, the excess will be treated as an extra Item for every 25kgs.

EG: A 30Kg carton will be calculated as 2 Items
An example of a calculation (received from Les on email)

Postcode 5067 = zone1 = Source
Postcode 3000 = zone2 = Destination
Cubic weight = 1.83 x .31 x .31 x 250 = 44kgs
Chargeable kgs = 44kgs
Rate for zone1 to zone2= .266c/kg + $7.46 Basic Charge = $19.17
Freight cost = $19.17 + 11.9% Fuel Levy + GST.

Is there any other plugging available as per my direct freight shipping requirements?

Thanks in Advance.

Shipping Director should be able to handle this.  It is very flexible, and can handle complex conditions and calculations.  The only thing above that looks a little trick is the "...extra Item for every 25kgs.", but I that can probably be handled with a Linq Sum() query.

Here's a blog to start with, http://www.noptools.com/blog/28/per-item-shipping-rates.  Notice it uses Items.Sum(Quantity).  You would need to use Quantity * Weight, and rather than just Weight, apply some function to it to handle "per 25kg" - i.e. some type of mod or something.

You may want to read a few other blogs to get a feel for other capabilities.
I'm not 100% clear on all your calculations above - feel free to use noptools contact page if you need more info or help in setting up your shipping scenarios.

Thank you.

I have Downloaded "Shipping Director". And Can you help me to how can I configure this?

How can I add my above requirements  in this plugging? Can You help me ?

Thanks In advance.