Off topic:
@MrWhippy
I also have the Asrock Z87E-ITX board. So you will probably have two mini pci-e slots of which one is occupied by the Wifi card. You can use both mini pci-e slots for a sata card with two sata connectors. Use one with an Asmedia 106x chipset. That one is not supported out of the box by Esxi, but you can easily use Esxi-customizer to inject the VIB file into the installation image. There are many manuals for on the net.
I use this one of Delock in de mini pci-e slot on the back:
http://www.delock.de/produkte/G_95225/merkmale.html?setLanguage=en
And this one of DX in de mini pci-e slot on the front (because it's only a half size slot, you will have to do a little bit of DIY to hold it in place):
http://www.dx.com/p/mini-pci-express-sata-3-0-expansion-controller-card-black-green-337644
On topic:
I noticed when I don't have a harddisk connected to the Lynx Point AHCI, it doesn't show up in Esxi and you cannot pass it trough. When I connect a harddisk it shows up again. So make sure you connect a harddisk when you try to make it work on Esxi!
@muellererwin
I searched around a bit, but I am afraid I couldn't find a solution for you.