relocating to kent or Essex

[Kapkap]

Hi, need advice as to best places to stay with easy access into East London. Don't know these areas at all. Have been living in Berkshire for the last 16 years. We need good secondary schools for both boys and girls and a happy area which has allot of green space around, we like walking.
Were keen not to live in London because of living and housing costs and need space.