Solution for Electroplating Selenium?
I'm not sure of any conventional ways of electroplating selenium, but you could use a technique such as magnetron sputtering to spray a thin film of selenium onto another metal. Heck, you could even use glass or wood if you wanted to do it that way. And if you're going for thin, this technique can get you some of the thinnest, smoothest layers of metal out there. A major downside is that your source metal sample has to be pretty pure selenium. But still, I think It's completely worth it.

However, If you don't have access to one of these devices, They can get expensive. Most major colleges with significant science majors will have one of these or something similar to coat samples for electron microscopy, or other reasons. Be sure to check there before going off to buy your own. Also, there are legitimate YouTube videos out there that show how to make your one device for magnetron sputtering. Check out this one if you're interested.