When it's time to pick out the gowns for your bridesmaids, you'll want to find something that will be comfortable for them to wear and that they won't feel out of place in. It is customary for all members of the bridal party to wear the same style of gown. But that isn't necessarily a rule. If you want, you can pick out one particular color that each bridesmaid needs to stick to and have them choose the style that fits her individually. It's much easier to find what would be appropriate for the groomsmen than it is for what would be appropriate for bridesmaids.
Groomsmen normally wear the same style of tuxedo as the groom.
Again, this isn't a rule, just what customarily happens. You do, however, want all your groomsmen at least wearing the identical tuxedo. To add a bit of style to your wedding, you may want to even consider having them wear bow ties that would match the color of the bride's maid's gowns. The bride's mother traditionally picks out whatever gown she wants to wear. Then the groom's mother follows by choosing a gown of similar style.