|Firstly good choice of SSD, i have one of these and its seriously good.|
All the machines i have built with SSD's have them either mounted horizontly using mounting brackets or fabricated brackets. I have also mounted a feww verticly on the case itself behind one of the doors.
The beauty of SSD is that they have no moving parts so really you have no issues with mounting them how you like, obviously taking into account that it gets some cooling from a fan.
Unlike the mechanical drive which have a spinning platter and a reading arm which moves continously, i hate to mount them any other way than horrizontaly, some cases force you to mount them in vertically because of the way the drive bays are designed, i would always fabricate or find a way to mount horizontaly.
With SSDs you can mount them as you like.
This is my view anyways, from experience and from videos i have seen and sites i have visted.