I think Dell actually bought Alienware a while back, not 100% though. Personally I hate Dell and I will never own another one. If it were me I would get a nice Mac Pro, but I know you can't since you have to run Autocad and ProE. I ran into those same problems last semester at school, I had to bring my Gateway desktop up to school so I could run Autocad and SolidEdge.

So I guess I would recommend Gateway, I've never had any problems with them but I have no idea what kind of performance they currently offer.