WoodITWork.com

HP has been creating its own customised ESXi images for while now which contain all the HP specific drivers and software which could be downloaded from somewhere on HPs website (unfortunately finding things on HP.com isn’t the easiest thing to do).
http://www.wooditwork.com/2012/03/28/hp-esxi-5-0-update-1-customised-image-available-for-download/

These images are now available to download directly from VMware’s site alongside images from NEC, Hitachi and Cisco.
https://my.vmware.com/web/vmware/info/slug/datacenter_cloud_infrastructure/vmware_vsphere/5_0#drivers_tools

Click on OEM Customized Installer CDs.

Direct Link: https://my.vmware.com/web/vmware/details?downloadGroup=HP-ESXI-5.0.0-U1-15MAR2012&productId=229

There are also direct links to HP specific documentation.

• Manuals – VMware Virtualization Software For HP ProLiant Servers
• ProLiant Server VMware Support Matrix
• HP Technical Whitepaper
• Driver Versions in HP supplied VMware ESX/ESXi images

This should make finding the images just that little bit easier.