My dad and I went thru the same struggle when we had to put our Lab down. My dad didnt want to get another dog because none could replace Jackson but over time my dad, his wife, and I decided we all wanted another dog in the house and now we have Kodiak, a chocolate lab.
While no dog will ever replace another, they are a new adventure and a new friend. Congrats on the new pup and I'm sorry for the loss of Hunter.