Howdy,
I won a national print award a couple of years ago for a body of work. What I created was printed on stock laminated with silver foil by allkotes. The way I approached it was to first print a white tonal base under what was going to be my skin tones for the image, I trapped it back a few dots first so we didn't get any halos, this was printed with oxidizing inks, we then went back and printed the cmyk over the top, both hits took a long time to dry as the foil does not allow the stock to breath, lots of hassels with the stock on the trolley as well, it wants to slide off with the slightest change in inertia. Depending on the creative for the job will determine whether you need to print the base white, printing 4 color on silver is like printing on 40% K, the inks are not opaque so the result can look dead and be an expensive waste of time. Putting the white down first gave it similar luminosity to printing on white stock, but beware you need to really print clean and bright as the white point of the printed white is nowhere near that of most stocks. The other thing to bare in mind is silver is only bright if it is reflecting light at you, so for example if you look at it held straight in front of you you will see you and what's behind you, if you put it on a table in the middle of the room it may look good and bright if it's caching the overhead lights.
You will need to apply a laminate over the final printed piece as it scratches real easy.
Hope I didn't bore you, and you find this useful at least maybe to establish expectations with your client.