I have been researching various scripts/programs to add a search function, web form processing, and a calendar with permissions, to a website.

I am not interested, at this time, in writing my own or in using Google apps.

I am having trouble in finding reviews I can trust and am asking the sitepoint community for their recommendations as to the scripts they have used or read about, specifically for:

1) Web Site Search: html, pdf, MS Office docs, blocked directories and/or files, and advanced features to include blocked words and specific phrases.

2) Web Form Processing: ability to send email and/or to a database, validate fields, validate matching fields, show errors without opening a new page, redirect thank-you page after submission.

3) Web Calendar: multiple sub-calendars, view without logging in, and multiple user logons/permissions to add/delete events.

I am using:
Operating system linux
Apache version 2.2.15
PHP version 5.2.13

I am not opposed to paying for the best script/program available today.

Any and all help/suggestions are appreciated.

Thank you,