HELP,hardware compatible with pfsense 1.2.2

[wanqf88]

Hello,all
   Recently ,I want to replace my current gateway with pfsense, so I need to buy a new server which is compatible with 1.2.2.
   I considerate using DELL HP or IBM 1U server with raid 1 hard disk array, so which one can I choose?If people here have experience on it , please give some advice.