I can do this job in aprox 3 days. The 3 days comes from the time we spend agreeing each other.
About what is better (JS or html), i think it would be better if you give me the html, because the JS consume processing of the client machine, assuming that the script that i will made will consume processing too, its conveniente to have the most possible part of the data processed.
I am a senior developer, so i can assure that i will do my best to have the most clear and documented code possible.
Any doubt you have, please contact me.
Regards,
Patricio.