Penguinoid,
By train it is less that 2 minutes from Forest Hill to Honor Oak Park, so it does not make a big difference which station you are closest to in terms of time taken commuting. What really matters is whether the flat/house is right for you and if you are happy in the street. The proximity to local shops, parks, and how much you like hills (and views) are also worth considering.

Personally I'm very happy living close to the centre of Forest Hill. It takes me less than five minutes to walk to the Horniman Museum & park, the station, cafes and supermarket. But I have lived in houses and flats in the area that are much further from the centre and you get used to walking for 10-15 minutes to get to a wider variety of different places.