I did a simular job before, for a jokes from website to mysql database. I also have some experience working with XML/CSV files.
Let's do the following:
Can You give me an example of your xml/csv files, and a link to your wholesalers site, and I'l try to do the job no matter who you'll choose at the end. If I manage to find time for the job, I will give You a link to working example and if it's what You need - we'll talk about money, if not...well, it will be my loss of time, not yours :)