best way to get my 5 Druids to 35 for alchemy/tailoring?

i already have a set of 5 mages at level 60

im assuming fastest way would be to get level 8 and than start boosting dungeons

but that would leave 1 character behind

if i were to level the alts by themselves

would Feral or balance be the leveling spec to go for?

Since you already have 5 mages at 60 you should be able to boost 5 druids by rotating them out periodically to keep all 5 of them at close XP when resetting dungeons.