You'll have a difficult job, Q6600 Multiplier is unlocked only from 6-10, 12 isn't an option. 800Mhz does the job he needs it too, & Quad core helps it last a little longer in future, A TB of storage well If he doesn't need it he can do way with 1 of the HDDs, but it's unnecessary spending of £100 or so if he's not going to be able to use the performance gain it can give him. Even people with money to burn look for bargains & value for performance, It's just the odd ones that don't that get noticed for burning their money.
Edit: I didn't mention before but at 1:1 with the FSB at 266 the RAM would be at 533Mhz, Underclocked to near half it's speed, now if the FSB is set at 533Mhz then at 1:1 The RAM will run at the 1066Mhz it's supposed too... Any less an FSB than that the RAM will be underclocked.