hi optimist,
as far as i understand, in britain you have to be enrolled for three years, no matter how much you have already done before you start (so even if you have been doing a PhD for two years at a different university, and are simply changing uni, you might very well be asked to enrol for the full three years again).
in other countries things are not that strict however. you could try germany or switzerland. as you stated, in these countries some PhDs take a long time because people teach and do research support work for their professors. but this is not a necessary requirement - particularly if you are self-funded, you do not have to do this (although, academic job chances post-PhD are reduced if you do not).