Plotting Markers on Google Maps

A budget limit for this small project is 60 EUR. It is a low budget because I assume you have already done something similar which you can modify and reuse. Only freelancers with a good experience with googlemaps and PHP projects will be considered. I need to display a large number of points on google maps. I need you to: 1) Create a large textarea, where I can paste any number of rows from excel, each row has 15 fields. This is important - I do not want to import the xls file, I just want to copy and paste values from excel into the textarea. You can save the file into MySQL database or use PHP array - it is up to you what is faster to do. 2) 2 of these 15 fields are lat long coordinates, and you have to display marker for these coordinates. 3) 2 other fields contain date:time and duration, e.g. 1.1.2011 20:00 and duration of 3 hours. The script has to find out, which date:time fully or partially overlap. Markers for rows that do not overlap will be displayed using a small green marker while Markers for rows, where time and duration fully or partially overlap will have a different marker. 4) when user clicks on the marker, 5 of the 15 fields will be displayed as a comment bubble. Thanks!