eBay Listing Design HTML Scripts for Button Links like Buy it Now and also Sidebar Other Items

I've created my eBay Listing design using full custom HTML but i need 2 other functionalities inside the Listing HTML. I have a general awareness that these funcionalities are done using javascript but i don't know how, so that is where you come in :) 1) In the eBay Listings template, i want to add my own buttons but i don't know how to dynamically create the link so that it includes the ebay item id. The buttons i want are: • 'Buy it Now' • 'Make Offer' • 'Watch Item' 2) In the sidebar, i want to display other items from my store. This is easy to achieve in the eBay Store HTML because you can use the 'Special HTML Tags for eBay Stores'. But for eBay Listings HTML, there are no such tags by eBay so i'm guessing javascript comes into play again here. Of course i need to be able to style this using CSS how i want. And it would be nice if i had some control over how many items are displayed and which items are displayed, like for example 'random items from a specific category' or 'lowest priced items in the store', etc. But the ESSENTIAL thing is that OTHER ITEMS are displayed. If you can show me proof that you can achieve this (by example of previous work) then that would give me more confidence. Any questions, please let me know. Thanks.