I stayed at the Brasilton for two nights a couple of years ago. Nice king room with a view, great restaurant and a deceent lobby bar made for an enjoyable stay. It was not too far from my customers, but I'm not sure of the proximity to the financial centers. Traffic in Sao Paulo can be horrible.

I've spent the most time at the Hotel Deville at the airport. Nice restaurant and lobby bar, full business ameneties.

Another favorite is the Ibis hotel in Jardim Europa. Close to one of the large malls and several nice restauarants.

Best of luck.