Making cell values correspond with Drop down List values

My title is rather confusing, but my question is quite simple. I have an invoice sheet with a drop down list in every cell in that row containing different rentals. When you pick a rental from the list I want its corresponding price (listed in the inventory sheet) to appear in the next column. I also was wondering if it was possible to start typing the name of a rental in the drop down list and have a list appear real time that shows the closest few matches and then one is able to pick from that list instead of choosing from an extensive list of rentals. The attached file should clear up any confusion.

Hello jrcream,

I created 2 named ranges INVENTORY_PRICE and INVENTORY_ITEMS on the Inventory sheet. This will make maintaining your code easier by not having to change all the ranges in formulas that use this information. When you add or delete information from the range, just change the range address. I added this formula to the "Amount" column...

 
  =IF(E16<>"",A16*C16*VLOOKUP(E16,INVENTORY_PRICE,2,FALSE),"")

This looks up the rental in the range INVENTORY_PRICE and returns the price for it. The formula was dragged to fill the remaining cells. This has all been added to the workbook. INVENTORY_ITEMS is list of the rentals including a blank line.

Sincerely,
Leith Ross