the 310 comes in both sizes. It comes as an msata and also a standard 2.5" 9.5mm. We sell the 310 2.5" drive currently as an slc cache drive. This drive may seem quite expensive compared to say normal mlc ssd, but what you want for cache drive is slc flash.
Following a chat with Tech Support it appears the there would be no spare PCI-e slot for it to be installed in in the Optimus II
It's a shame as the quote from Intel looked really promising:
"The small footprint of the Intel® SSD 310 Series also augments hard-disk drive (HDD) performance in dual-drive systems, such as all-in-ones, notebooks and small-form-factor desktops. The mSATA form factor connects easily to an existing mSATA port on a PC, which enables the Intel® SSD to perform as a boot drive and provide quick access to frequently-used applications or storage."