STOP RIGHT THERE!!!!! no, its not ok to put them in the same tank, they will just eat eat other like allmost strat away!!! only a very few tarantulas can be keeped in a comunal tank, even then it is not advised and people allways report there tarantulas being eaten by the other ones. so NO, itd not ok to put them in the same tank.
As pete said there are some species that can be kept together sucessfully, but i have found it needs careful planning and watching when together on food levels and interaction. I went on holiday and one ate another - think they ran out of food. But none the less it is an interesting thing to look at. But do extensive research if you are thinking of going that way.
I think H. gigas is one of the only terrestrial spiders that can be kept together but i could be wrong. But i wouldn't recommend the species you have for communal set ups.