Monitoring uptime website(s)

I am looking for a program (serverside) that checks the uptime of a website. - has to monitor more than one site - interval of monitoring manual set per site (every 1,5,10,15,30,60,360,720, 1440 minutes) - send a SMS (for example through [login to view URL]) and/or an email include a BCC email after xx minutes when a site was down and send it again after the site is up Please make a first bit on the discription above. After this program is working I want to have the next option: - check the load time of the page - a weekly overview of the average loadtime per day and week - an overview of the errors including time out - overview has to be sent by email for each site (with BCC) extra option - daily and or weekly SMS with the average loadtime and errors