Where to get internal oak doors?

[Stillunexpected]

We have finally decided to replace our flimsy internal doors with decent quality oak ones but where does anybody recommend? Have had a look online at Homebase and Wickes and will check in real life at the weekend but don't think the quality looks up to much. So can anybody tell me where they have bought their doors - either online or in real life?

[poppet131]

Howdens - sourced through our carpenter.