I can't comment on submans Phenom figures, but the 4870 run too hot. With the 4850 you get very good performance for a lot less money and heat.
Submans CPU charts were interesting to say the least. I would however consider that the E8400 overclocks really good. Mine runs 3600 Mhz (a 20% increase) without any ceremony, and would probably go higher, if I push voltages / cooling.
Don't know about dollars, but E8400 are priced at 120€, E8500 at 160€ and E8600 at 220€. So with the E8600 just 666Mhz / 20% faster it's fairly obvious that the E8400 is the price/performance champion among the Core2's.
In addition there are very mature and cheap boards based on the IP35 / IP45 chipsets, like the Abit IP35-E I'm running (really fast & stable board without unnecessary features for just 75€).
Tip: save some money on the CPU and video and invest in a really good
PSU. I personally recommend something like the Corsair 650TX, high quality cables / voltages for <100€. Loose cables were the number 1 stability issue with my last build! So I'd rather not get cable management, it will only create problems.
P.S. I copied you the list of what I got (prices from two months ago but have not moved):
Mainboard:
Abit IP35-E
RAM:
Crucial DIMM 4 GB DDR2-800 Kit BL2KIT25664AA804 ~95€
CPU: E8400 ~125€
Heatsink:
Thermalright Ultra-120 eXtreme ~50€
Video:
Sapphire HD4850 1024MB ~170€
PSU: Corsair CMPSU-650TX
~100€
HD:
Western Digital WD6400AAKS 640 GB ~60€
Fans (CPU, Case):
Scythe Slip Stream 500upm
And everyone should have a look at those WD 640AAKS. Almost the optimal HD, with a two platter high data density design. In practice nearly as fast as Raptors, but cool and quiet, and for half the price! I got two of them, the second one for images and backups.