Asp, Php, Xml, Txt?

Hi all. Im about to start work on something huge and feel that i may be over my head even before i start. I have dawn out a plan to create an online specialist search engine. I will be using a linux based server and I am wondering what would be best to use. ASP PHP XML or a Simple TXT. As for automated inputing the data it wont be a problem either way (I have worked on a few ideas for that before and it seems to be working well.)

That data that will be requested is simple text layed out in a table with the specific sub sections and links to the third party. If you look at google but on very limited scale (working nationaly) with links to members subscribed to the service. If you have any information of what would be best. I would be grateful. I promise to keep you posted on how this works out. It should be amazing when it works out.

Many thanks

Scott