I am for sure an Intel person so I am liking parts of the build already. I am not sure exactly what uses you plan on having for this PC, it seems to me like a Media Center PC.
I am not to sure about the Dynamo PSU cause I have never heard of it. How many watts? If its only like 400 there's a good deal on a 430 Watt Thermaltake
As for your CPU, not exactly sure which 2.66ghz you are talking about, theres 3 of them. Hopefully its not a E6750 that I see here at NewEgg that it's 179.99, you could spend the same exact price and get an E8500 which is a 3.16ghz core 2 duo built on 45nm vs 65nm architecture, also it has a 6mb cache vs 4mb.
For sure go with an Intel motherboard if you want a solid computer, just do not go for the cheapest one cause price does equal quality and ability.
As for a chipset stay away from the 945, 955, 975 chipsets cause they are a bit to old to keep up with today's new technology. I myself like the P45 chipset, usually they run DDR2 800 ram and can support all of their processors except the Extremes I think.
I like Seagate hard drives. I've had mine for some time now and never had any problems with it. 5.1 surround sound speakers are nice but I myself would drop the money for the speakers into a better video card, but again I am not sure exactly what your plans are for this PC.
Maybe some links to the actual hardware will help us see exactly what you plan on making.