@skbedford the quick answer is yes! Although not always true, many bags that are available in a left and right zipper option are designed for exactly what you describe - to be zipped together! And if you stick within the same brand and the same/similar models for both bags, you are very likely to find a combination that zip together nicely! In the case of the REI Magma, this will work! One thing to note is that if you purchase a petite length in one bag and long length in the other, your zippers won't align perfectly at the top, however they'll still zip together just fine! Hope this helps!