"Waiter! Please give us two bowls of rice."
If counting bowls you would use 个 (我有两个碗) i have 2 bowls. Here 个 is the measure word for the bowls. When counting bowls of something (我有两碗米饭), i have 2 bowls of rice. Bowls becomes the measure word for the rice. Hope that answers your question?
Both are acceptable, 个 can be used in many situations but may be less accurate but equally correct nonetheless.
I happen to live in China and no Chinese person would use 请给 unless the person they were asking was of a much higher class and they need to 给面子 give face.
Regardless of the way it would be said in a certain location, the given ENGLISH sentence here includes "please" and to fully translate the given sentence (and thus learn more) the Chinese should have 请.