Gizmo Andretti

Hello, We are looking at buying computers for our school to run Second life. I'm wondering if Second life takes advantage of hyper threading and multiple CPU cores/thread? If we are only running one instance of second life viewer, will it take advantage of an i7 with 8 threads? or will an i5 dual core perform just as well? Also, would dual 1GB AMD HD 6450's be fully used or is that overkill? The computers are set to get 8GB of RAM. We want secondlife to run smoothly and look good, but also not break the budget on computer hardware. Thanks