3000 skus in one drop down list seems very unwieldy. Perhaps you should consider alternatives that produce a shorter list of values in the first place.
You could set up a conditional value list where your "similar items" are assigned a category. Select a category first and get a list of only the Skus that are members of that category.
Or you might find it useful to set up a "search portal" where you enter text in a field and you get a list of partially matching items in a portal where you can click on to select it....
they do have quick lists where they can choose product group and see smaller more focused lists.
a search portal options seems worth exploring. - thank YOU
You may find this demo file to be of interest then: https://www.dropbox.com/s/0pm1gdqcfi2ndpv/EnhancedValueSelection.fp7
FileMaker 12+ users can open this file from the File menu to get a copy converted to the .fmp12 file format.