Oh, interesting. Looking at the coding for those specific items for the build, I can easily add an achievement to it. At the very least, I can add that soon.
It gets complicated, though, when you start thinking about "customizing" it all. I could, theoretically, build a page that lets you choose between the categories (one mouse, keyboard, etc). The problem is with the finished item - what if you personally chose I don't know, a green gaming mouse, a pink monitor, and a black keyboard while someone else went with and orange mouse, etc etc. We certainly can't do item images for all that!
The only way I see working is getting a few items that are like "Riverdale Custom Rig" or "Arctic Rig" where on the backend I could set a few combinations that could produce that rig and y'all figure out the combinations. I'd set it up like flower bouquets (because hello code is already done). Right now, the computers are all marked as toys and have that option to play with your pet. Other than an achievement for x builds, would that really be worth it all?