Better Search?

I’m looking for a plugin that will let me manage my search better.
I want that my search results will show, not by date like now but by relevance. For example if i search for the word “cat” the first results will be the posts with the word cat is in the title.
Plus, right now when searching i get only 4 results per page, is there any way to change it with out changing the number of posts showing in the front page?

Thanks