Water shutoff valve for refrigerator
If there's a shutoff requirement a single valve will satisfy it. There's no need to use two. The kind that installs in a box in the wall behind the fridge are a little more intensive to retrofit but they're convenient to use. I can't speak to whether you might have state or local codes that require this in-wall style -- and I'll wager the Best Buy delivery crew aren't trained on the subject any better. In most places a valve at the supply end of the tube is a fine an alternative to the recessed box behind the fridge.

Line kits often include a self-piercing saddle valve. It's a pair of half-round straps, screws to squeeze them together, a 'stinger' on the inside which pierces through existing plumbing, and a small pin as a handle to operate the valve. They're easy to install but they're always junk. They restrict the flow and they eventually leak at the site and/or the valve won't close fully when you need it most. Use this valve only as a last resort.


It's much better to have a normal valve installed appropriate to the kind of plumbing in your home, then adapt it down to the 1/4" tube for the fridge.