I'm jumping in here and I'll state up front that:
a) I've never used the CCK, and
b) I know nothing about RAW image files.
There, now you know that my knowledge is limited but, why not look into CloudFTP by Hyperdrive (I do know a little about this), as it will enable the iPad to connect wirelessly with USB mass storage devices including; Ext HD's, USB memory sticks and cameras. If this is of interest to you you would need to do a bit of research as to the capabilities in relation to your specific requirements but I will help as much as I can as I have purchased one of these and have done a fair bit of research myself.
The Archangel