I got the ESXi installer to recognise the NIC now... but, just like you, having installed ESXi the hard disc that is was installed on no longer shows up!
Arrrgh... so annoying. Its weird because for me, the HDD doesn't even show up as a bootable option. I get "Windows Boot Manager" and and all the OTHER hard discs, etc.... but choosing "Windows Boot Manager" doesn;t do anything except trip to PXE boot!