SERIOUS PHP EXPERT NEEDED FOR HIT STATS SITE

Hello, We have two stat sites in USE and we need to transfer a feature from one to another. Both stat sites run the same PHP stats script. First site named A reports the delivery of the hits by simply dividing the total hits number by TWO (example: If 100,000 hits are delivered, it shows 50000). This 1/2 feature is turned ON for all campaigns currently on site named A. Second site named B reports the delivery by adding a % of every new hit. Like if you set up the counting system to 20%, it will add 0.2 hit when 1 hit is received. So when I change delivery from 20% to 30% it only affects the new traffic to 0.3 instead of 0.2. The main problem is that the function on site A divides all numbers by two (total delivered so far, delivered today etc...) So if I change this 1/2 function to 1/3 then the total traffic being reported as delivered will change and we will lose traffic served so far. Example; a campaign currently showing 50,000 as delivered and finished will show 33000 delivered only out of 50,000 (contract amount) and all our customers would then claim their campaigns are not finished. So we need to keep the 1/2 feature on site A enabled to all exiting traffic campaigns to avoid having the total delivered numbers changed/affected and have the new feature transferred from site B to site A enabled by default to new traffic campaigns only. If you DISABLE the 1/2 feature on site A, all campaigns which have received over half of the contract amount, like 55000 out of 100,000 hits ordered. Then the "Total delivered" number will be multiplied by two which would make 110000 delivered out of 100000. Then the active campaigns will automatically go to the completed group which would cause massive customer complains. There will be no change through this project on site B because we will only copy a script feature from it to site A. The site A is heavily used by active users and tons of active traffic campaigns that move every second. If you put the site A down, this can't be done for longer than 30 minutes. You must do backup of site A files and database but you should restore them in case of big failure only since the data on site A change every second. I would prefer to have the site A temporarily down then keeping it online and have a restore older than 15 minutes restored. The site A is very important so data losses will NOT be TOLERATED. Please DO NOT bid on this project if you are not FULLY SURE you can accomplish this project without damaging the script or causing data loss. THIS PROJECT CONSISTS IN KEEPING TWO FEATURES WHICH ARE NOT COMPATIBLE WITH EACH OTHER ACTIVE BY POINTING ONE TO EXISTING OLD TRAFFIC CAMPAIGN AND THE OTHER TO NEW TRAFFIC CAMPAIGNS. REQUIREMENTS: 1) YOU MUST BE AVAILABLE ON YAHOO MESSENGER OR MSN DURING THE WORK SO WE CAN COMMUNICATE AND I CAN ANSWER YOUR QUESTIONS IN LIVE THROUGH CHAT. 2) YOU MUST BE AVAILABLE ON YAHOO OR MSN CHAT (TEXT CHAT) AT LEAST 4 HOURS DAILY. WE DONT WANT PEOPLE WHO GO ON VACATION/HOLIDAYS WITHOUT HAVING THE PROJECT FINISHED. 3) YOU MUST BE A SENIOR PHP PROGRAMERS WITH MANY YEARS OF EXPERIENCE (5 YEARS MINIMUM REQUIRED). 4) YOU MUST PLAY SAFE AND MAKE SURE NO DATA IS LOST DURING YOUR WORK ON THE EXISTING SCRIPT. DATA LOSSES WILL NOT BE TOLERATED. 5) NO TIME WASTERS PLEASE. I LOST 3 WEEKS WITH A PREVIOUS CODER ON THIS PROJECT WHO DOES NO LONGER REPLY SO I DON'T WANT TO LOSE ANOTHER 3 WEEKS. Great feedback will be left if project successful! Please post PM if you have any questions.