Speaking about buying/selling bootlegs or other unofficial material is a good way how to get banned on this forum. There are 3 “official” versions of Harmy’s editions, a mkv file, an AVCHD and a DVD-9 (just movie I think). All of them are usually available at the same places, just read the thread Bluto linked and also “The Ultimate Introductory Guide” ( https://docs.google.com/document/d/1yLsvexWBVM8IYSGopKuSfsGk5YIgCwQWd23bqb5ryD4/pub ).
The extras as far as I know are available only on BD, most of the people here don’t use DVDs anymore, sorry.