Carmen, I think you may need to go Kydex on this, and what's more, to go custom.
There are a lot of Kydex folders out there who make items for the Shield, such as these guys (I've never used them before, it's simply from a Google search)
http://www.werkz.com/made-to-order/pist ... rrier.html" onclick="window.open(this.href);return false;
^ Who, as their website picture shows, offer items for the Shield.
From there, seek out custom attachments, such as the paddle attachments offered by the following (again, I've never used them before, it's from a Google search)
http://daraholsters.blogspot.com/2015/0 ... hield.html" onclick="window.open(this.href);return false;
In all honesty, I would first try to contact either of these makers (or others like them) to see if your chosen maker simply can't be a one-stop-shop for you so that you can get the magazine holder and the paddle attachment in one go. This will minimize any potential adaptability issues you may have from cross-shopping different makers.
With the magazine-holder/paddle example I gave above, for example, if you were to use those very specific items, it's more than likely that the spacing between the mounting holes in the paddle will *not* match the offset of the mounting holes in the magazine holder (which is most likely much wider apart).
Also, would you entertain a Kydex double magazine pouch with the use of these clips?
http://www.detroitholster.com/store/pro ... eed-clips/" onclick="window.open(this.href);return false;
They will hold the pouch close and tight to your waist, while allowing you the ability to (relatively easily, versus, say, having to undo your belt) remove and re-mount the pouch on your belt.
All that said, I leave you with:
http://shop.blade-tech.com/product_info ... caNbPmOdps" onclick="window.open(this.href);return false;
They've also got their own paddle attachment -
http://shop.blade-tech.com/product_info ... caOLfmOdpt" onclick="window.open(this.href);return false;
^ I'm not familiar with their paddle attachment, though, and I'd encourage you to give them a call to insure that it's compatible with that "Classic" Double- Shield mag pouch. Typically, with Blade-Tech products, I use their TekLock....