Stallard Technologies looks good for Dell cluster HPC servers. Check their Youtube channel for overview of HFT hardware
http://www.youtube.com/user/StallardTechnologies?feature=watch
UPDATE: Their shopping cart is SCREWED where you cannot get shipping options like UPS. Not useful so I move onto competitors!!! Looking at Velocity Systems
NOTE I now post my TRADING ALERTS into my personal FACEBOOK ACCOUNT and TWITTER. Don't worry as I don't post stupid cat videos or what I eat!