Array formula to remove blanks (like autofilter)

Hey everyone,

I've been trying to figure out what I believe is a simple problem but I can't get it right. Attached is a sample spreadsheet that will hopefully illustrate my goal more clearly.

I have several customers that order various items. However, they do not all order the same things nor do they all receive the same prices due to volume, etc. So what I'm trying to do is that when I select the customer in cell J3, that columns I and J fill with the non-blanks from the table in B4:E19. My assumption is that the items will have to be referenced from the costs but I'm not totally sure about that since there would are non-unique prices.

This is essentially an auto-filter problem without using the built-in function but I swear I've had something like this set up before. Thanks for any help.