I think there was a Joe's program to move stuff from the SDB to the inventory, and vice versa. Though I'm not completely sure.
You should check on the programs section
(you need an account to see links)
Also, your browser and basically nothing works because with so many items, the page becomes, as you said, overloaded lol
Loading so many actions, even with a program or the quickstock is kind of hard. You should use the lightest browser you can find. If you have Windows 8, try with internet explorer.
Don't use firefox. I love it, but it uses a lot of resources. I don't know about chrome, I don't like that one that much.