2 questions about electronic drumkits + Sonar

Hi, I'm about to pick up an electronic drumkit. Now i'm wondering is there anything i should know of before buying one? I know they range from 300 dollars to 1000's. I was planning to spend about 500/600 dollars. I only will use it to record with Sonar. Any recommendations and do's or dont's? Also i'm wondering is it possible to have several pieces of the drumkit panned to left or right? I mean you record it as one track i assume so it would suck if every piece sounds like it's coming from the same place. Know what i mean? Thank you!!