I'm sure all universities are keen to have their medical students go on and contribute to research as part of their career, so stating you wish to do so shouldn't be a problem. Just be ready to justify yourself if they ask you "why not study a science degree then?"
Intercalating a BSc in a scientific subject will definitely help you get your foot into research. There programmes ant Oxford and UCL (and I'm sure other unis too) where you can do an MB PhD. So you get to graduate with a medicine degree and a PhD, but this takes an extra 2-4 years depending on your PhD project. Doing that will definitely help you further into being an academic clinician, but you've got to have the academic record at medical school to justify them putting you on the course (usually is decided before you start your clinical years).
Of all the unis, probably Oxford, Cambridge, Imperial, UCL, Edinburgh and Newcastle (I think) try to encourage people to do research in particular - though from my understanding all medical schools do like students doing research.