Does Apple sell 16GB RAM? Can't seem to find it... Currently it's 4GB Can I upgrade the Graphics card? Currently it's: Intel HD Graphics 3000 with 384MB of DDR3 SDRAM Can I upgrade the CPU? Currently it's: 2.4 GHz Quad-core Intel Core i7 Also: - If I get an external Thunderbolt 1TB HDD will a 256GB SSD make a big difference to the performance (noting that I'm losing half a TB of internal storage)? - Any other ideas on how to keep this lappy viable for a few more years? Thanks in advance everyone!!