The SFF can only accommodate the PSU that is in the chassis and the PSU comes in
one flavor. The processor however can be bumped up provided you're currently on a processor of the Sandy Bridge platform which is lower than the i7-2600. According to the
technical documentation, your highest gain on CPU will be that of an i7-2600 while your ram is 4x4GB 1.5v DDR3 @ 1333MHz.
You could add an add on card but you would need to look at an HTPC grade GPU like the GT740 or lower for power draw concerns alone.