I dont have a wide knowledge on very good inexpensive parts.
Don't stress out too much over selection of parts. Look for balance - like don't spend half your bucks on the graphics card. First off, decide on if you can stretch a bit more, it's good to do it now rather than live with the new box anxious to upgrade. Remember, 1000 is significantly above 700 and so list off everything you have to have:
Case
PS
Mobo
CPU
Ram
Graphics card
Optical drive
HD
Keyboard and mouse
Monitor
OS
Games
etc.
Next, be sure you can't pirate some of the above from an existing system. If you already have monitor, keyboard and mouse, you now have significantly more to spend on the core of the system. Once you have some ideas in mind for mobo and CPU, go to the forums on the manufacturers web sites, here, etc and see if you can find and preferred combinations or conflict problems. Look at what you can get as a complete package online for 1.5 to 2x the price and you may get some good parts combo advice.
While you're at it, shop around. I got great dals on my big rig's parts by just being patient. Some people want to buy it all at once but I spaced it out over about 6 weeks. Don't forget to ask sales people or online stores about rebates, upcoming sales, etc. Compare on ebay. when people see what I paid for my parts, they freak but it was all just finding deals. I probably averaged 20% off of retail.
Patience, Grasshopper, but be ready to jump when a deal arises.