Spiff -
I just built a new computer myself and I think I can steer you in a better path. If Roger is a gamer, than you should be looking at AMD processors and not Intel. AMD performs better for gaming apps and gives a little more bang for the buck (you can get a near top line AMD 64 3500 processor for the same amount as the Intel). As far as the motherboard goes, I went with the MSI Neo4 SLI board. This board gives you PCI-Express (important for using current and future video cards) and has the SLI feature that gives you the ability to use 2 video cards at the same time (NVIDIA cards only).
As for RAM, I would check out Crucial's website
http://www.crucial.com , which has a very handy wizard which will recommend the best kind of memory based on your needs (gaming, value, graphics, etc). I also like Corsair and OCZ also. As for the video card, I would recomend either a Nvidia GeForce 6600GT (a good one would cost around $160), GeForce 68000 ($200), or the GeForce 6800GT ($285). The NVIDIA cards have been pulling away from the Radeons recently and Radeons do not yet offer you the opportunity to run two cards at the same time). I would also consider having a power supply of at least 450W. These new gaming apps are real power hogs. I went from 400 to 480W and saw a difference in my PC's performance. Hope this helps.
As far as the burner goes - I think the Plextor 716-A is the best one out there, at any price.
