perweightunit questions

Version 1.3.8a

I need two different shipping methods.
(1) if a customer buys 1 of 3 products (only of these three), then they will have free shipping. there is no reason for a customer to buy more than one of these items.

(2) If a customer buys any other items on the website, then shipping is charged according to weight. (peritemweight)

Shipping is simply calculated. It does not use UPS, USPS or anything else.

I have freeoptions turned on. Then I have weight and cost set to 0.

I have freeshipper turned on I have shipping cost set to $79.00, set to taxable goods. no shipping zone.

Then I have perweightunit turned on and set to 1 where it says this...
The shipping cost will be used to determin shipping charges based on: Product Quantity * Units (products_weight) * Cost per Unit - in an order that uses this shipping method.

Here's what I want (in a perfect scenario)

A customer buys a product (with free shipping) and a product (that pays for shipping) Whenthey check out, they see one shipping price say $129.00 - $79.00 (promo free shipping for MT250), then the final price of $50.00.

If this is not possible, then only show a shipping price of $50.00

Also, I need help with setting up the shipping charges. The client wants to have a different rate for each .5 pounds. up to 120 pounds. Ouch. Is there a module for this?

Is what I'm asking possible?

Thank you SO MUCH for your help.

I'm new at this, but I'm still going to ask a very stupid question.

Why doesn't anyone reply to my posts? I look above and below my post and all have answers. Is there someone who moderates these boards?

Where else can I go for help.