You can give him a disc with
Portable Firefox with
Epub Reader Plugin or
Lucifox (I hadn't heard of that one before) installed on it--download the portable program to a flash drive or memory card, install it there, open it & browse to the epub reader plugin & install; put the whole folder on a disc with ebooks. (Portable Apps also has a couple of PDF readers that are smaller than Adobe Reader, and don't require installation on a hard drive.)
Baen also has the
Fifth Imperium CD collection--discs that were sold with the hardcover books, containing complete series of ebooks. Legit, free to share & copy.
You can also check out the books at
Feedbooks.com; those have PDF options, including custom-sized PDFs.