I have more than 4 years of experience in Joomla development, from the simplest websites to complex systems. I have even worked with Virtuemart this week, just look at my profile, the one called "Project for renvon" was to make a plugin work with virtuemart.
I even started your modification to a virtuemart testing website that I have so you will see that I know where to look in VirtueMart to do the modifications you are asking for.
You can add this product to cart: [login to view URL]
Then check the cart here: [login to view URL]
On left side of "Name" column, I have added a checkbox :)
On first link you can also check the plugin that wasn't working with virtuemart and I corrected it for the employer (webrotate360).
I hope you will choose me as your developer.
Kind regards,
Lucas