Wordpress (jigoshop) Plugin needed

Hi there!! I've installed the jigoshop extension on my wordpress website. Now I wanna customize the "Related Products" part. I have 50+ products on my website. But, now I want to explicitly define some of the products to display under related products(just for 3 or 4 products). I've gone through the jigoshop extension page, I found that I need to install an extension "Up-sells & Cross-sells" for this purpose. (I dont know either this is the solution to my problem or not.). So, I want to buy this plugin in low price. Please contact me If you have this plugin and this plugin can solve my problem. Thank you!