I used to use a Phottix Plato on my D700 until I put the batteries in the receiver backwards (in the dark) and melted it (smelled great!).
Now I use a Vivitar VIV-RC-200-D300. It's cheap and it works great. I don't know for sure, but I assume it will work with the D800 too. If you want to send me your D800 for a few weeks, I'd be happy to test it for you!