Thoughts on bringing another whippet into a only dog household?

Hi all, I’m new here.
My Dash is a pedigree whippet from a rescue, 5 and a half years old, we have had him since 10 months. He is such a spoilt only dog and his whole world revolves around us! He still has some separation anxiety from previous homes.
We want to adopt a Candy Cane Rescue whippet type (from China - rescued from the meat trade) but unsure whether a dog or bitch would be better, or younger or older. When we look after a neighbour’s older terrier crossbreed for a few weeks every year Dash can be a bit of a misery guts.
Generally Dash loves meeting other whippets and dogs his size, age and intelligence (low! but not sure how he could cope living with another whippet? Has anyone else been in the same situation and can give advice?

Thanks a lot! Hope everyone is well.

Likely be better with a bitch. Could you offer to foster and see how things go then you would not be committed if it didn't work out well.

We get extra dogs for ourselves, not for our dog. Most dogs that have had their owners to themselves will enter a state of armed truce with a new dog, some will be very happy to have a 24/7 new dog, some very unhappy. You won't know if this will work until you do it, and it all depends on the personalities involved. Think how it would be for you if your life partner brought another person home and told you they were staying.
So I'm not saying "do" and I'm not saying "don't" I'm simply stating the practicalities.