Javascript Guru needed for:- Live Data fetching and filter, Import and Export spreadsheet pricing.

I already have the program, it's running in a good condition, need to upgrade / tweak the mechanism. I don't mind if the project needed sometime to do it's not very urgent but i don't need programmer doing trial and error. I need: A) Programmer who is a Javascript expert. B) Who knows Google Chrome extension C) Knows how to handle API fetching D) Committed and able to advise me which method is the best. 1. To improve data fetching from a constant updating URL. 2. Need to filter and fetch data correctly for google notification 3. Need to create dynamic spreadsheet, where it can store data and can be searchable for price comparison. 4. It code is ready however it needs to be perfected, you don't need to reinvent the wheel.