System Usage from Most to Least Important: Productivity, Speed/Performance, Gaming
Parts Not Required: keyboard, mouse, monitor, case, CX430 V2 Builder Series
Preferred Website(s) for Parts: newegg.com or amazon.com
Parts Preferences: I would like Intel if possible, but am open to AMD if necessary to fit my budget.
SLI or Crossfire: Maybe in the future
Monitor Resolution: 1920 X 1080 would be great, but is not necessary
Additional Comments: quiet, low cost, low power usage
Specific functions: Home PC, School, Word Processing, Programming, some Gaming (LotRO, LoL, MineCraft)
Goals: Easily upgraded in the future, Compatible with Linux OSes, Most Speed/Responsiveness while computing (not gaming)
Let's focus on general computer speed (CPU and Memory) and not Gaming capabilities (GPU).
I've looked at Tom's 500 build, the focus on the 560 card seems cool, but too focused on gaming performance.
i3-2120 / H61 MB is right starting point. Go with integrated graphics. When you start wanting better gaming performance then add the card. (aside $90 for hd6770 above is a steal, that's a nice card). Your build has all the right parts to include any card you want later.
+1, get the i5 2450 at $150. Aside: the ivy bridge i5 might drive up your MB price a bit. Make sure your MB *SHIPS* with a bios that supports ivy bridge. Having a MB that is UPDATABLE to ivy bridge won't help you unless you have a supported CPU to apply the firmware update to the MB.