Trying to choose best Desktop system upgrade route

[jediphx]

I have a max of $700 to spend.

Some suggestions have been the following:

Intel Core 2 Duo E4300 Allendale 1.8GHz 2M shared L2 Cache LGA 775 Processor - Retail

SAPPHIRE 100201SR Radeon HD 2900XT 512MB 512-bit GDDR3 PCI Express x16 HDCP VIVO Video Card - Retail

mushkin 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail

GIGABYTE GA-P35-S3L LGA 775 Intel P35 ATX Intel Motherboard - Retail

Thermalright XP-90 Multiple Heatpipes CPU Heatsink - Retail

or

AMD Athlon 64 X2 4000+ Brisbane 2.1GHz 2 x 512KB L2 Cache Socket AM2 Processor - Retail

CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail

BIOSTAR TF560 A2+ Socket AM2 NVIDIA nForce 560 MCP ATX AMD Motherboard - Retail

SAPPHIRE 100201SR Radeon HD 2900XT 512MB 512-bit GDDR3 PCI Express x16 HDCP VIVO Video Card - Retail

I have been out of the hardware loop for a while so any suggestions would be appreciated

 

[jkresh]

if you dont want to overclock then its borderline, if you are willing to oc then the intel system will give you a lot more headroom.

 

[Sinn707]

First build is a lot better if you are willing to overclock, which is very simple when you have an E4300 and atleast some aftermarket cooling on your hands.
By the way, Thermalright XP-90 is AMD only. It will not work with Intel cpu's. I suggest getting Freezer 7 Pro from directron.com for $20 or so.
Good luck.