Devon is lovely! We moved here 18 months ago when kids were 4 and 6. I would suggest that you spend a week down here exploring as there is a very big variety of places, both very rural (Dartmoor and north Devon), semi-rural in some of the towns, and 'urban' (well, as urban as you can get in Devon - Exeter, Plymouth, Torquay). Do you like the sea?
Not knowing you, your kids, your preferences or your situation (e.g. do you need access to work, or transport links? do you need to buy a property?), it is impossible to suggest a specific place, but there are primary schools nearly everywhere, many of which are lovely village schools in real communities, where I'm sure you and the DC could make a very happy home. Check out the Ofsteds, visit the schools, and visit the villages/towns to figure out what you like. After spending two weeks on holiday here, we decided on the basis of landscape (prefer the gentler rolling hills, rather than the supersteep!), proximity to the sea, and access to a great village primary and in the catchment for a great secondary.
Good luck, and if you have specific questions, am happy to address, like the poster above. Don't worry about moving the DC - it is not irresponsible if it is the right decision for your family. It takes a little while to settle in, but they won't look back - and nor will you!