I was planing to buy another of the same ssd at a later time and raid0 them would 256gb be enough for a few games I play alot and the boot drive?. which higher quality power supplies brands/specific models would you recommend?
There's no higher quality units, only with a higher efficiency, the XFX 850 XXX is made by seasonic, the HX series is now made by channel well (anything above 650W), the AX is a seasonic oem unit, the same for the seasonic psus.
The XFX 850 XXX is 80 plus silver, the other units might be 80 gold, but the difference is really minimal, not worth spending more, this might help you : http://hardocp.com/article/2011/10/04/80_plus_irrelevant_to_you_when_buying_psu/2
A 256GB ssd is a good option, it will have space for more games, the 128GB might be not suffice for that.