The one I have is a fold up one so it gives me a template. I'll work off that but upsize it a little and getting the LED lights in the top shouldn't be too difficult, there's loads of that sort of thing on the interwebs. The LED's I have in my current one can change colour tone with four settings but I might see about adding something different also, some colours and maybe a light from a different angle so I can cast shadows into the lightbox. It's a work in progress.
You're right too, there's a satisfaction derived from making something oneself.
It's pretty amazing what they can do with LED's these days. You can get them in pretty much every shape and color for whatever you need them for. Those strips they have just blow me away.