If you get married you don't need a work permit. If you are coming over on a fiance visa, you can't work until you get married, though I guess the UK employer could get you a work visa...but they have to do all the work - you'd just have to fill out forms & apply for the entry clearance on your end after they get you the work visa - there is only one kind & I'm not sure with your education that you could get a work visa (your company would have to prove that they can't find someone in the UK or EU that can do your job as well as you can).
Best bet - get married, get the married person visa, then get a job!