Hey Baku! Good to see you.
He’s a great cat. Cuddly and will walk on a harness!
It’s an unpopular place but maybe you could bust someone out of The Lost Dogs Home. They tend to have compatibility/personality blurbs. Other choices might be Lort Smith, 2nd Chance Cat Rescue, or Friends Forever. There are timid cats and cats that are really chill with other cats but I don’t have much experience in introducing them. Maybe try watching Jackson Galaxy.
I’d recommend a senior cat because they can be calmer but to be honest while they’re the best ones (according to me) they tend to need more frequent checkups and need a bit more in vet costs if there’s any health conditions. Upkeep is usually a fair bit more than the initial cost of a cat.
Edit: Maybe an adult cat, because they will be at a good age to tell whether they have a similar personality. A kitten hasn’t settled into that yet and could be too boisterous