As far as benchmarking.....there are lots of different ways to do it. It really depends on what you want to know about the systems. A very good one is Sisoft Sandra. It can be found at
http://www.zdnet.com under downloads. Just type in Sandra and it should come up. Other benchmarks are Quake 3 (which is widely used for OpenGL gaming benchmarks). I would recommend getting the final demo which is available on
http://www.3dfiles.com. That should give you a ballpark figure. There are tons of other games and benchmark suites that you can try...but....those two will get you started. As far as burn-in benchmarks.....you could try 3dmark 2001 and loop it over and over to test stability of the system. Also, the Sandra program has a burn-in part and it will run tests over and over and over.....(or you can set it to run a certain amount of times). Hope this helps some! Have fun benchmarking!
jcwagers