My current tower system dates back to August 2005 and was built using the following components:

ABIT NF8 series m/board, AMD A64 3000 CPU, nVIDIA GeForce 128MB GV-N66128DP graphics card, 1024MB Corsair XMS 3200 RAM, 250GB Sata HDD memory, OS = Windows XP (currently running Windows 7 Pro)

I now wish to replace the above with a new system to run Windows 7 / 8.

I do not run games, but do wish to run a Flight Sim (probably FSX) at the highest resolution/detail.

I have been advised that Flight Sims do not require anything like the GPU power required to run a modern game, but that a dedicated graphics card would still be advisable, rather than rely upon an integrated system.

I am looking for a system along the following lines:

i5 quad core CPU, 8GB RAM, 1TB memory, Windows 7/8 Home Premium

Q1. What dedicated graphics card spec would be indicated for the above described use? Can you identify both specific GPUs and also a more general GPU spec?

Q2. Is choice of motherboard critical?

My budget is £500-£650

As an example, John Lewis are currently offering a HP P6-2185EA tower system, for £629.95. Spec includes:

2nd Gen i5 3.3Gz CPU (dual core??), 8GB RAM (no manufacturer specified), 2TB memory, Wireless mouse and keyboard, Windows 7 Home Premium (64 bit)

The on-line spec states that graphics are handled by an " AMD Radeon HD 7450". I read a not very complimentary review of this graphics card, but I think it was on a gaming forum?

(see: http://www.johnlewis.com/231577565/Product.aspx)

Any alternative vendors/models?

In the event of any problems, I would like to be in a position to return the PC to a designated drop-off point, rather than get involved with packing/shipping. This is one of the reasons that John Lewis is an attractive vendor.

Any help/suggestions ref the above questions would be gratefully received.