Intel Xeon Server Proc for Dell - Intel Packaged vs HP

I have a Poweredge 1950 with the rev II board. It currently has dual E5335 2.0Ghz procs which I want to upgrade to the fastest possible. According to the matrix at http://en.wikipedia.org/wiki/Intel_Core_%28microarchitecture%29, it appears that the X5365 is the fastest I can go within that series (Cloverton quad).

There is a large price variation in the market if I buy the bare proc as an HP version versus a standard Intel. Here are two examples:

Intel : http://cgi.ebay.com/INTEL-XEON-PROCESSOR-X5365-3-0GHZ-QUAD-CORE-CHIP-SLA4P_W0QQitemZ370257716638QQcmdZViewItemQQptZCOMP_EN_Networking_Components?hash=item563514659e&_trksid=p3286.m20.l1116

HP : http://cgi.ebay.com/NEW-HP-PROLIANT-SERVER-XEON-PROCESSOR-X5365-436520-001_W0QQitemZ140348981769QQcmdZViewItemQQptZCOMP_EN_Networking_Components?hash=item20ad738209&_trksid=p3286.c0.m14

Will the HP work in my Dell, or does it have some goofball proprietary stuff on it?