I'm thinking of doing Maths, History and Economics for sure but not sure with final option (A Levels). I would like to do PPE at Oxford
Thinking of either Further Maths(Don't really want to), Sociology or Psychology.
Or Art and Photography (I would like do to this but I'm not sure Oxbridge will care)
What do you think?
I doubt very much they'll care what your fourth option is as long as you get a good grade in it. PPE doesn't have any required subjects, and you're already doing both of the 'recommended' subjects (history and maths), so your third and fourth options should be subjects you enjoy and think you can do well in.
Why did you write "PPE at Oxbridge" given a) it's only a degree course at Oxford and b) you state you want to go to Oxford anyway...?
There is no point taking a 4th subject unless it is FM - you will be spreading yourself dangerously thin compared to the FM option (which has cumulative content with the main A-level Maths syllabus and reinforces your revision in that subject) for zero benefit. I don't get the impression FM is a specific benefit in terms of admissions, but it may well be useful background for undertaking the course if you are actually admitted, particularly if you are interested in focusing on the economics part.
If you aren't confident you can get an A*/A in FM, stick with three subjects. If you are confident in your mathematical background, aptitude, and motivation, then it's a decent option to consider. There is no reason to take another subject, especially not an art/design subject in your case, as these take up enormous amounts of time.