The Network blurays for S1999 are going out of print according to the Official Gerry Anderson Facebook page. I'd get them while you can. Seriously stacked.
IF you can, get the seperate S1 and S2 boxsets as there are a lot of the extras dropped for the complete series set. And I mean a LOT.
-- "These Episodes" documentary (selected individual episode analysis: "Breakaway", "Matter of Life and Death", "Black Sun", "Another Time Another Place", "Guardian of Piri", "Force of Life", "The Last Sunset", "Voyager's Return", "The Full Circle", "War Games", "The Troubled Spirit", "Space Brain", "Mission of the Darians", "Dragon's Domain", and "The Testament of Arkadia") (95:18)
-- "Memories of Space" featurette (7:16)
-- "Sylvia Anderson on Live Action" featurette (16:13)
-- "Horizon: Space: 1999 Behind the Scenes Footage" featurette (2:29)
-- "Concept and Creation" featurette (12:38)
-- "Special Effects and Design" featurette (16:52)
-- Space: 1999 Year 1 Textless Generic Titles (1:44)
-- "Clapperboard" featurette (Special on Gerry Anderson; edited to remove non-Anderson footage) (38:59)
-- "Guardian of Piri Remembered" featurette (1:38)
-- Barry Gray’s Theme Demo (1:23)
-- Alternate Opening and Closing Titles (2:58)
-- 1975 Introduction to Series One (with Landau and Bain), from US station KRON-TV (1:54)
-- Effects Plates and Deleted Effects Scenes (silent, with music) (11:41)
-- Alien Attack Trailers (x3) (3:38)
-- Journey Through the Black Sun Trailer (1:53)
-- Ad Bumpers (0:38)
-- Lyons Maid Ice Lolly Advert (0:29)
- DVD-ROM material:
-- 13 Script PDFs
-- Space: 1999 annual PDF
"Unexposed: Behind the Scenes of Series Two" 1976 documentary (25:07)
Stock Footage Archive (mute) (46:02)
"Cosmos: 1999" featurette (13:21)
Martin Landau Interview (44:53)
Outtake (0:27)
Promos and Trailers (10:42)
"Behind the Scenes: Model Shop" featurette (6:35)
Clean Titles (4:00)
Production Audio:
- The Taybor (26:18)
- The Rules of Luton (41:36)
- The Mark of Archanon (16:08)
- Brian the Brain (29:56)
Archive Interviews:
- Martin Landau (5:41)
- Barbara Bain (4:28)
- Gerry Anderson (4:33)
- Catherine Schell (3:17)
- Keith Wilson (4:11)
- Brian Johnson (6:42)
- Fred Freiberger (6:47)
DVD-ROM Material: Most of the scripts from series 2 and the annuals (in PDF format)
There's also the Bringers of Wonder - Destination: Moonbase-Alpha film version that was limited to the slipcase edition of S1. I've got the two limited edition seasons with the lovely slipcovers - the first is limited to 1000 but with I think 5 variant covers so I guess limited to 200 each. Then the S2 set was limited to, well, 1999. My copy is a wee bit scuffed.