I think that a UV filter is a waste of good money which should instead go for a good lens hood, and is likely to have on overall detrimental effect on your image quality.
Todays lenses are pretty tough already and have excellent coatings that stand up to cleaning very well. UV filters are easily broken, and provide little real protection for your lens compared to a good hard lens hood ( except for certain situations - see article below).
Here is an article on the topic by Mike Johnston, whose The Online Photographer blog is very well-respected: