Hi,
We can't just spend a day to work on that for you to get that eaxact result. If you need a developer to work on that for you, you can contact our partners:
www.hikashop.com/home/our-partners.html
We can however provide pointers and hints for specific questions if you have any.
For example if you edit the file "invoice" of the view "order" via the menu Display>Views you can see that code:
<?php
if($this->config->get('price_with_tax')){
echo $this->currencyHelper->format($product->order_product_price+$product->order_product_tax,$this->order->order_currency_id);
}else{
echo $this->currencyHelper->format($product->order_product_price,$this->order->order_currency_id);
} ?>
which displays the unit price with or without taxes based on the taxed prices display setting of the HikaShop configuration.
So here, you know how to display a price thanks to the format function call, and how to get the unit untaxed price of the product and how to get the unit taxes amount.
And just below, you can see the line:
<?php echo $product->order_product_quantity;?>
which displays the quantity of the product.
So just with that and basic PHP knowledge, you should be able to calculate and display the necessary information you want in your invoice.