You may want to look at PowerCLI script that pulls the Host System Information. Something like GET-VIEW. However I am uncertain if it can pull items like version of DRAC (Dell) or ILO (HP)
Something like this may work.
$Test = Get-VMHost -Name "your ESXi Host" | Get-View
$Test.Hardware.Systeminfo | Export-Csv -NoTypeInformation -Path "C:\Scripts\report1.csv"
$Test.Hardware.Systeminfo.OtherIdentifyingInfo | Export-Csv -NoTypeInformation -Path "C:\Scripts\report2.csv"
Also there are a few posts located here that goes into the more detailed info you can pull from GET-VIEW.
http://tech.zsoldier.com/2011/08/hardwaresysteminfootheridentifyinginfo.html
http://www.virtu-al.net/2009/07/08/powercli-host-hardware-one-liner/
The fact there are other posts means you are not alone in trying to get this information from vCenter. I believe a majority of what you want can be pulled from vcenter and host using PowerCLI. Its just getting the correct attributes of Hardware View info.
-Boston TechGuy