You don't need super fast cards-- you're not watching videos straight off the card and even then, these would probably be fine.
I've happily used these http://smile.amazon.com/gp/product/B00M55C1I2/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
and these http://smile.amazon.com/gp/product/B00P3NMVGA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
I load them using pmw and a USB3 card-reader/writer (have to Add Device and select the card in pmw) and they load at about 19mps, whereas the pono loads at about 3.