I've never seen an OEM or similarly well built aftermarket dual snorkle scoop seperate. But there are some flimsy versions that could. Your link shows a Six Pack scoop on a Duster hood. It's a bit big, but also functional.
http://www.bigblockdart.com/forum/images/dto_garage/users/10549/1033.jpg
http://www.forabodiesonly.com/mopar/attachment.php?attachmentid=1714619494&stc=1&d=1368639189