"Does anyone have any reservations about any of the below specifications or what I should definitely choose to upgrade?" - Depends what you're going to be using it for.
If you were to build it yourself, you'd get double the hard drive space (click here), better quality RAM (click here), a better + quieter case (click here) & better speakers (click here) for around the same price.
Btw, there's ~£50 difference between an E8400 & E8500 - do you think you'll notice the difference in games or in general? G