if you are thinking to remove the drive later and connect to computer, you will not be able to read the drive. HEN can not get the required encryption key. even if you had CFW, you would only be able to read (not write).
after you install the drive, you can copy ISO from USB or use FTP over network. if you have not already ripped your discs, use multiman to rip straight from disc to ISO.
use this to split the files into 4 GB chunks and then use multiman to copy them from usb to internal drive (press triangle and then select copy). multiman will put them back into one file as it copies.