Does anyone know of a reputable Online broker for investing in international shares, mainly US.

I'm sick of paying ridiculous rates with NZ brokers, getting terrible execution of orders and having to place orders the day before when they are in the office.

I could open a personal account with TD Ameritrade Fidelity or Merrill Lynch, but I can't find one that will open an account for a company. It doesn't have to be a US broker.

Any help would be appreciated.