-Get a VNF3-250. Unless you're desperate for performance (or need gigabit ethernet) the VNF3 is a decen t performer. If you're desperate for OC'ing, wait until a NF4 board comes out, and get the Winchester version if you want to overclock, as it performs 10% better per clock than its single-channel cousin.. (which I'm guessing yo do). Also, budget the additional 20$ for a SLK-948U with AS5 and a Panaflo fan, as the Silent Boost is not the world's greatest HS for OC'ing.
-Spend less on your case and power supply. Most included PS's are junk, and aspire is no exception-and with the amount you're paying You can get a plain (but functional and easily modded) aluminum case from Newegg for 25$, and a CoolMax 400w power supply (with a five-star rating) for 40$. This will save you about 25$ now, and perhaps a few hundred later when your PS dies, taking the rest of the system with it. You'll need a few fans, but you would most likely replace a few of the ones on the ASPIRE-X case anyway.
Also, look into getting cheaper RAM. NewEgg has a 1GB kit (which you'll DEFINITELY be wanting-512mb is a major bottleneck) for 200$. Kingston has a rep for high-quality RAM, and they're 50$ cheaper than two of the FireStix modules.
Also, consider going for a slightly lower-end graphics card. A 6800GT-OC is great, but a non-OC'd version can be had for 300$, and with another 512mb of RAM you'll be getting better overall performance anyway.
Also, you might want to consider waiting for the NF4 based boards, which should be out by the end of the month. Wait a few weeks, and you'll most likely be able to get an Asus or Abit NF4 ultra board for 120$, which gives you PCI-E and speedier hard drive interfaces along with all the features of the NF3.