You cannot possibly hope to do this with javascript. And I think it's a much bigger job than you realise.
You would need a script on the server side, where the end user could not see what was going on, to grab the information from the wholesaler. Who knows - if you're really lucky, they may have an API you can use. Otherwise you're stuck with rather hard parsing problems. Javascript is not up to that job.
I always vote for PHP. It's not actually all that hard a move, if you're reasonably competent with javascript, and there are many amazing things you can do with PHP, including database access (which again might be something you'll be needing).
To put this all into context, my gut feeling is that you're looking at a couple of weeks of flat-out development for a job like this. I guess you'd be paying a professional anything up to $2,000 for the job. So you aren't going to get a complete solution, asking a few questions here I'm afraid. But we could give you some pointers.
Your first pointer, if you really want to do this, is to learn PHP. There are a lot of PHP tutorials out there.
JMO.