i have similar issues with back and knees, i found the mokka,kamiq and 2008 just that bit low for me. the best i found in your price range were the nissans juke and quashqai. ive gone for the juke hyybrid nconnecta on wpms its £631 but on pip/dla its 499. the quahqai under £500 is the base model so may not have the spec you would like.