I don't farm gold with barb so don't know what skill/passives are best, i'm sure someone else will assist you with that. Although I think leap would be a good one for movement.
I couldn't guarantee it but if you get your pickup to at least 40 and movement speed to 25% whilst keeping your gf at above 250 then you would get over 300k gph.
I think with my DH at around 255% gf, 40rad and 25% ms I was getting around 340k+.