OP, beware though as some cats really don't get on with other cats. Cats mainly like human company, some are great with others, some not so much... I have 3 and they generally get on okay now, but when I brought her (cat hater) home, it was like a war.
I had got her from Gumtree when I was 19 and DP and I were living together for the first time (cat less at the time as my other 2 were at home), we just wanted a cat that would mind it's own business, so we weren't bothered when we were told about her personality (violent, unfriendly etc), they said they were rehoming as they were worried she was going to attack their 2yo. Got to the house and the victim toddler was running around chasing her, trying to grab her, she was terrified, they said after 2 years, she still didn't know her name. :(
She was very violent, would attack if you were in the same room, depressed, un neutered, skinny, missing teeth and most of her whiskers, big slit in her ear. It wasn't good.
She is now the fluffiest, lovey cat ever unless you are a cat she is a total lapcat and learned her new name in less than 2 weeks and out of my 3, is the best with my 2 toddlers! She is lovely.
I guess what I am trying to say is, taking on a cat from a not great background can be brilliant, but it can be a long hard road trying to get them back to their former self. If you take on a rescue that seems like a bad case, it might not be a good idea to try and introduce more kitties in very soon.
Anyway, good luck OP with whatever you do, I know whatever kitty/s you get will have a lovely home. :)
Here's mines here.