Best 3G Internet for 1-week stay?

I am staying in Puerto Plata area for 1-week (arriving Saturday). What is the best 3G Internet service in that area?

I need to buy the USB stick for my laptop, and want to have unlimited 3G for 1-week only. I guess I need a prepaid plan.

Am I better off with Orange, Viva, or Claro.
How much should I expect to pay for the USB adapter, and how much should I pay for service for 1-week?

I am buying this for my AI resort because they only offer us Internet in the lobby area (for a fee), and I need to connect very often for business.

VJS said:

with orange 3G stick: ~50 USD for the USD stick, and ~130 pesos daily, so for the week 130x7 = 910 pesos

Click to expand...

What is the 130 pesos daily plan called? Is it a pre-paid thing? Which plan do I ask for? How much data transfer do I get? Unlimited 3G?