GSM or CDMA for mobile email and database?

Dear Bluggers,

I have to set up a mini wireless network for basic internet access at the
Beijing Convention Centre in early June.  They do offer ADSL feeds but the
prices are astronomical.

I'm thinking about buying a GSM (China Mobile) or CDMA (Unicom) SIM for data
use, and an appropriate PC Card for a Windows laptop.  I would love to hear
Bluggers' experiences with the relative merits: I understand that CDMA is
faster than GSM, for example?

Main usage will be for perhaps 3 to 5 simultaneous users doing basic email,
and to access an Oracle database via a browser app.

Best regards in advance, and I will summarise to the list.

S.