Am I Dumb, Crazy Or..................................?

Hi to all from Germany.(I am from N.C.) I have a few question and hope to learn alittle here in this forum. First the background. I would like to build my first computer. I have own 2 over the past 10 years and it is time for a new one. After researching the net for 2 months and waiting for the prices to fall enough for my budget to build a good gamer pc,this is what I have come with:

-Intel Core 2 Quad Q6700
-Scythe Ninja Mini CPU Kühler SCMNJ-1000
-Asus P5N-D NF750i S775 FSB1333MHz ATX PCIe
-2x2048MB OCZ DDR2 800MHz CL5 Vista Performance Platinum
-500GB Seagate ST3500320AS Barracuda 7200rpm SATA 32MB ;5 year Warranty
-EVGA Geforce 9800GTX 512 MB PCIe ; 10 year Warranty
-LG GSA-H55L-R LS DVD Burner
-750 Watt Power Supply with 135mm (5.3in) Fan
-The ATX case I have chosen has 3 temp. sensors, digital control over the internal fans and is supposed to be easy to install all the components.

This set up is on the edge of my budget. So, everyone here tells me I would dumb to try to build my own computer. My problem is for $60 more as the above system, I can get this prebuilt system:

-Intel® Core 2 Quad Q660
-Original Intel Kühler
-Same Mainboard
-2 x 2048MB DDR2 800M´MHz (No Name given)
-512MB Geforce 9800GTX 512MB PCI-E 2.0( No name given)
-SATAII 750GB 7200rpm 32MB Cache (No name given)
-20xDVD-Burner DOUBLE LAYER Lightscribe ( No name given)
-LC-Power 550Watt Power Supply with a 120mm (4.7in.)Fan
-A ATX case with an internal fan

Both sytems have at least a 2 year warranty. So my Questions are:
1. Am I crazy for wanting to do this? I have never done this before. I do have 2 friends
that could help me if needed. 1 of them said it would be better to buy the pre-built system because if I have a problem, I could send the whole thing back, when I build one and have a problem that we can not figure out, I could be in deep doo doo.
2. I have looked and find nothing to this question. Does the Asus P5N-D have ide connectors that my old dvd needs that I want to add and the new DVD burner also has or do I have to buy the DVD burner witk SATA connectors?
3.Does anyone have a suggestion about a better component than what I have listed on my wish list?

I would like to buy a 2nd Graphic Card alittle later when I can afford it to go SLI. I will say the prices in The U.S. are somewhat cheaper that here, So a $50 upgrade there is sometimes a $100 upgrade here. Any help would be appreciated. We are 6 hours in front of the East Coast Time so I may not be able to answer comments or questions right away. Thanks for your time and hope I did not bore the Pros out there.