I don't think it sounds like a huge dilemma. The jobs you get in the future and any teaching you get while you're doing your PhD will depend largely on your PhD topic. What exactly is your topic going to be? If it's English, presumably you'll have supervisors with the appropriate expertise who should be able to offer you teaching in your subject, even if the actual departmental affiliation at the uni might not seem logical. Not everyone is attached to a dept that exactly matches their subject, and several on this forum, including me, cross several disciplines and departments in our choice of PhD topic. Though I have been aware recently of needing to align myself with certain depts more than others, so it's more obvious on paper where I 'fit in' when applying for future jobs....