Employee Portal Lookup Searching

HI there.
I need help with the following.
I have created a Sales order Quote Card and List where users can enter sales Quotes and everything works fine.
My issue is that I have lookup fields, for which i need my users to not only be able to look up let's say on the customer card, but also search by customer name and or No. just like they do in navision. This one client of mine has 10000 customers and 30000 items. I do not except him to click Next and Next and Next until he finds his customer or item and than select it to insert on the Forms.
Has anyone done this before ?? Searching on a lookup form ??

THanks