My local auto store doesnt stock 24" and 16" dual wipers but they do have 22" and 18"......would this fit without having any fitment problems or miss any spot on the windshield??

 

22" will give you 1" missed area up top where the sun visor portion of the windshield is, no big deal.
18" would possibly chafe against passenger side A pillar. One way to fix it is to take off passenger side wiper and rotate it 4 or 5 notches up towards roof to clear the A pillar.
But then you'll have a crooked wiper.

 

just buy wiper blade inserts from the dealer way cheaper then buying replace wipers from else where

less then 11 dollars for for replacement wiper blade inserts at the dealer