If you really really like History & want to do it at uni, then I'd say two history courses might be good. However there is a chance you will absolutely hate History A level as its quite different than GCSE, so you might not want two Histories in case of that. Although I loved History at GCSE & still love it at A level
My school doesn't offer Ancient History though, and the first time Politics is being offered is for the current year 11s - which is kind of annoying, because I wanted to take it
I have looked at a couple of Politics textbooks, though, and it does look quite good. Obviously I have no idea what the exams are like though!
I dropped Philosophy & Ethics in early year 12 and ever since I have regarded this as a massive mistake. Like the other subjects you've chosen, it's massively essay based and the subject matter looks quite interesting. I know the people at my school who do it find it quite interesting, and I really really wish I hadn't dropped it.
Are you taking three A levels or four? If three, I wouldn't take the extra History - you want a wider range of subjects - but if you're taking four then maybe. Personally I'd go with politics over philosophy, but you really want to look at the pros and cons of each and decide for yourself. As far as I know those two are pretty much equally respected by unis
You might also want to look at how much of the courses are assessed by coursework vs exams at your school.