1/2 oz of chinook used at 60 minutes will put you right at the beginning of most of the stout styles for bitter levels, they start at 20 IBU's for a Sweet Stout and roll up to 50 IBU's for an imperial. At 60 minutes, depending on your AA values that would fall into the 35 IBU range.
Now a single hopped stout with Chinook would work, but Chinook is the hop that smells and tastes the most like you would imagine – a dank piney forest. These hops are known to have a very spicy finish. I find that this flavor is great compliment to Mt. Hood or cascade used as aroma hops and would pair it up with another for aroma.
The choice is yours, may be a good time to experiment and familiarize yourself with a single hopped beer.