Hello,
Following are the options you have. But it will be a good idea to confirm them (I can not say that I am 100% accurate) before you take any action:
1. As a UK citizen you can stay here for 6 months duration. No visa needed.
2. Get a job sponsorship. Can be here then for 2+ years.
3. Marry her, you get your residenceship automatically !! Live for life.
Hope this helps.
ICT