A few questions, do you overclock? (if yes, mild? or serious?) What is your budget (in your currency)? Where do you live?
If you do overclock, make sure you go with one of the new 790GX or 790FX/SB750 boards as the new southbridge improves Phenom overclocking A LOT, about 200MHz-400MHz.
Thermaltake CL-P0369 MaxOrb Enthusiast CPU Cooler. $62.25
The best air coolers out at the moment are the Thermalright Ultra 120 Extreme and the Xigmatek HDT-S1284, both cost around the same price and outperform the MaxOrb by quite a bit.
Diamond Radeon HD 4870 800MHZ 2GB GDDR5 $619.99
I assume this is the HD 4870 X2? I would go with Visiontek, only ATi partner with a lifetime warranty.
@ Teny, HD 4870 X2 comes in 2GB (2x1GB) flavours only, so 1GB.
And please no Antec 900, I despise that case. There are better cases around. Take a look at the Cooler Master RC-690 or the Stacker 810.
Like the others have said, those prices are pretty steep, if you do live in the US or Canada, use Newegg.com/.ca