The easiest way to add bluetooth support is to just use a USB dongle. You would need to change the decal and lights at the front of the notebook even if you could install the Sony module - I would guess the price would be prohibitive.
Changing the hard drive is possible. You could change to a large capacity 120Gb 2.5 inch drive without a problem but a more cost effective solution would be to just use an external drive. It would also avoid you having to dismantle your notebook . . . .
