Personal opinion(based on first hand experience)-- Stay away from angoras and dairy goats(Nubians are ok).
You need to get some that have some body to them-- or they can't maintain their weight on pasture alone.
So look for goats that have a handspan between their front legs.
You should be able to buy some bred goats for $125 easy.
As with cattle-- buy from someone whos established and doing well with the same environment and system you plan on useing.
AVOID-- foot problems
goats get footrot and it ain't the same as with cattle
Its a contagious scourge to get rid of once it gets going.
Avoid worm problems-- either stock real light or have a three pasture rotation- where the goats are only on each piece once a year.
Goats eat pretty much anything if they are hungry enough-- but they have their preferances too.
And if they do get hungry better have a good fence