The internal memory is fairly small... only holding about 10 books at a time, depending on how big the books are. I have never had a problem with this, I just delete the books I have read off the device (keeping another copy on my harddrive) and load on the new books.
The type of card needed for the EB1150 is not a common one, its and older one and I believe not manufactured anymore? You can buy them off of ebay though.
I believe we have a thread in this forum about what type of power cord I think its this one:
https://www.mobileread.com/forums/showthread.php?t=30103
Amy