I live in East Sussex, moved here 30 years ago. If you have to live in the south-east but you want to feel as if you live in the south-west, then the High Weald might fit the bill. There's a huge difference in feel of the country between the Low Weald and the High Weald. Question is, do you want to be in a larger town, smaller town or in a village / country? What's more important to you?
If you need to be near a station, the best connection are Haywards Heath or Wadhurst. The Uckfield line is sweet (travel back in time 60 years) but not always super reliable, it has a reasonable service and lots of people do commute to London.
I think East Sussex gets increasingly more rural as you go east. (Low Weald) Haywards Heath - Newick, Newick - Uckfield , Uckfield - Heathfield (High Weald starts at Buxted) Heathfield - Dallington, Dallington - Battle. The country in between Heathfield to Battle is a lot less crowded than Haywards - Heath to Uckfield. North High Weald Mayfield, Wadhurst is more expensive than southern High Weald, Dallington, Netherfield, Battle.
My children went to school at the local village school then onto the local Community College. They did very well. Crime is low.
Ashdown Forest is wonderful. Beware the weather in Crowborough, being so high it can spend days in the winter in the clouds... quite literally. It does rain more in the High Weald than in the Low Weald due to its height. East Sussex is the most wooded county in the country, 17% of the land is wooded. Small irregular fields, high hedgerows footpaths literally everywhere.