I have two minerals I use. Manna Pro is for the bucks, it has a good cal/phos balance, and ammonium chloride. Southern states Top Choice is for the girls. It is higher in copper (and actually cheaper, go figure) than the Manna Pro, but the cal/phos is uncertain. I add just a little of the Southern States to the boy's minerals too, to give them that extra copper. I'm happy with their condition on both mineral types.
We use Kent's loose goat mineral and really like it. I've also used manna pro, I could never find any in 40-50 lb bags, so we switched when our herd grew to 100 (after the fire our goats and ourselves moved to Gunnison onto a friends ranch where we combined forces and share the goats now)