Many thanks everyone for the advice and the welcomes
! I do think that perhaps a slightly older cat or a cat with a disability would get the best lease of life with us.
From Hazel:
A really nice thing to do would be to contact rescues and ask if they have any special needs cats, eg deaf or blind cats. I know some people let these out too, but if you found one who had never been let out I think it would be safe to say it will be happy kept in. Another option is a cat who has been in rescue a long time, surely a flat is a better life than a 8x10 enclosure.
We did come very close to adopting a blind cat last year, but sadly we couldn't due to the other problems she had.
(We couldn't cover her for insurance because of her special diet and tablet costs. The poor thing was abused and as a consequence had lots of internal organ problems). It was very sad because she was a wonderful little cat, so friendly and always happy despite all the horrible things she'd been through and we met all other needs for adopting her. Luckily someone at the shelter very kindly sent us an email newsletter of rehomed pets and she was on the list
I slept easier after that email.
I do agree with you on the points you made. I do think an older cat would perhaps be better for us as we are in the right situation to provide it properly and not stress it out in a constantly changing environment.
From Lilith: (That's a really interesting name btw, I have a good friend called Lucy who likes to be called Lilith and loves cats to bits! She owns several though, and they are all outdoor cats
)
A lot of people suggest, get two kittens and they will be company for each other - and so they will, but not if you're houseproud. A playful cat can leave devastation in its wake, never mind two! I had the most beautiful long romantic lace curtains in my bedroom before manic Molly demolished them lol (not!) However she's an extreme example.
I see no reason, especially with all the thought you're giving to it, why a cat shouldn't have a very happy life in your flat, with enough company and any fragile valuables protected. Also you might need to think ahead if you have a balcony - catproofing a flat could be a good subject for another thread. As has been said, a cat in long-term shelter accommodation would think it was great, and a special needs cat would be ideal.
I have heard from a lot of people to get 2 kittens so they don't get lonely. Generally I think that would be okay if we were out a great deal (AKA 9-5) in our jobs we are very lucky and work for several different clients. So there are days where we don't go out for more than a few hours a day. I think perhaps we won't go down the kitten route for reasons you've mentioned. We both really want to adopt from a rescue centre rather than buy from a pet store where you can't always trust the places they get them* (see below for reasons). And also We just got a new sofa. (okay it's nothing special, we didn't sacrifice our mortgage to get it, but still, it would be nice to keep it relatively claw free for now)
We do have a fairy large balcony and we live on the second floor so that is something we are also going to have to prepare for in the future. Luckily we have fairly high railings so that should provide a little deterant. My BF and I have talked this over a great deal and we have concluded that with the type of balcony doors we have installed we need to just be very vigilant when we do get a cat. However any advice on this is also welcome.
*I have nothing against pet stores, independant or chain. I always found them to be wonderful places with helpful souls. The thing I have discovered over the past few years though is the breeders of animals that sell to pet stores are not always on the level. In fact sometimes they can be a damn sight inhumane in their practices. I know it's not so common in the UK anymore, but it is common in Spain, where I currently live. I have asked pet stores here over the past few years for breeding certificates and they can't provide them, or the place they gave me just does not exist. (FYI, it's just a billing address in the city, in a location impossible to hold animals safely in multiple) So (it's sounds like I'm being terribly anal right now...... :/ ) I decided a little while ago to opt for rescue centres above all else. I have many other reasons for this, but that is my main one.
*faints*) 
