How to effectively integrate an upsell on specific products?

I am currently building a shopify site for a retail store that mainly deals with fishing products. I wanted to allow the customers to choose if they want to have the fishing reels they purchase come pre-spooled with fishing line and was unsure of the best way to go about this. I would prefer to avoid leaving that as an option variant and it would save a lot of work if I was able to only have this option appear on the fishing reel listings.