Ended up moving my server over to an Intel NUC D54250WYK Haswell i5 with attached storage. Ah, the advantages of running a VM. Intel finally released this low-power desktop system and it seems to work great with Esxi 5.5, with the addition of a few drivers.
The problem is described here. However, in fact, the driver the author provided for the e1001 did not work for my system. I used a combination of the 5.5 iso (VMware-VMvisor-Installer-5.5.0-1331820.x86_64.iso), ESXI-customizer 2.7.1, and two drivers, the e1000 (net-e1000e-2.3.2.x86_64.vib) from here and sata-xhci (sata-xahci-1.5-1.x86_64.vib) from here. I've provided a mirror for the drivers and the customerizer on dropbox here.
The ESXI-customizer takes care of most of the nitty gritty, so just follow the instructions there for adding the drivers, one at a time.
VT-d and PCI passthrough seems to work just fine with this hardware.
