We had a 2 year old pup who was killed in a car accident. We went out right away to find another one, but my mother was too emotional to choose one. So we didn't bother and time just went by with no new dog. Then my grandmother moved in with my parents, with her dog.
However, before my mother passed away, she told me that she always wished that she had gotten another puppy.
So, I say, go ahead and get a new kitty as soon as you can see through the tears to choose one. It will not be a replacement for Snoopy, because cats are each different and loveable in their own way. But it will be a companion that needs your love and care too. And if you rescue one from the Humane Society, that will really be an act of love.