The main difference is that one is primarily in book format and the other is mainly video. "Complete" is a good book to have around because you can use it as a reference at the gym or for giving others a look. The DVD with the book is just a demo of each move.
"Encyclopedia" is an in-depth look at the basic KB lifts. It's one of my favorite DVDs. Most everything I do and teach is on there.
Of the two, I use Encyclopedia a bit more but both are good.
BTW, these are about the best prices you'll find:
stores.ebay.com/Martial-Arts-Videos_Stre...idZp4634Q2ec0Q2em322
Good luck.