Skeelz are still used in elo, mainly in mono deck though. i still like to use all-stars when marina and saki are unbanned. montana actually are a bit out of the scene now because avola and mona just got permanent ban. they are still though thought, just not as much. jungo are also seen a lot of times so i'd say all of those 4 are still pretty usable =)
Can you recommend any particular builds or cards needed for Skeelz, Allstars, or Jungo then?
This one seems pretty legit when marina and saki are unbanned: http://www.urban-rivals.com/presets/?id_preset=2603926&list
also, this is the skeelz deck that i've been using: andy ld, chiara cr, dr falkenstein, michael (you can also use aylen, she's more than usable), plunk, redra, sasha and sandro. there's also people i know who used snowflake instead of andy and they did just fine. that person actually went over his last record with this deck (same one but aylen instead of michael and snowflake instead of andy)