Hi
Just set up mine, using this: viewtopic.php?f=2&t=2147
except that I boot from SD.
I inserted a blank micro-SD (2Gb) and also a 2.5" HDD from a notebook. You can put a SSD, but you don't really need speed there. You can mount it in the optical drive bay, or if you already have an optical drive, double-side-tape it above the RAM modules.
Very easy: use ILO console. Mount ESXI ISO from there. I used 5.1 as I read there are some limits to VM management in 5.5, and I didn't feel that the new features from 5.5 would be useful to me (mostly large capacities). If anybody sees something interesting, please explain.
Then, during install, press yes,yes,ok,keep going,yes,ooh yes, and when prompted where to install vwmare, choose ilo-sdcard or something like that.
After install, reboot. Start the vsphere client. You have to create the datastore on your HDD, and then tell ESXI to use it to store temp files (logs, etc.).
And you're done !
Edit: I tried both with Raid controller enabled and disabled, and then raw-device-mappings.
With raid controller disabled, I can actually see disks type, serial and especially SMART status, whereas in B120i controller mode I couldn't (shows instead generic information sent from the controller).