Building a specialized search engine

Hi People!

I'm planning to build a specialized search engine (like get it to search only all the websites within a state) I ain't sure about the features but it must has good relevance & high speed. I run through some open source software like nutch, dataparksearch, aspseek, lucene, etc and wonder which is the best and easiest to implement. As I'm still a beginner and learning, can anyone advise me on that? I'm not going for something of google size but still it should be able to index some millions of pages then search through it within the fastest time.