Malaria ~What are side effects of taking pills? and other questions?

We are traveling to S. Africa in Feb/2010 and will be going to Kruger Park known for it's high risk factor of malaria. What are side effects of taking the pills? I heard that they cause bad dreams and flashing lights~do they also upset your stomach? Are there better pills over others? Can you get a shot rather then pills? Again, we heard that having the shots means that you can't have alcohol? Any advance is welcomed. Looking forward to this trip, not looking forward to these meds...