I'm building a new system that I'll use for web surfing and some gaming (mostly WoW and Warhammer On Line after it's released).  I'm on a tight budget and the cheaper the better.  I'm also hoping to allow myself the chance to possibly upgrade the processor down the line.  I've chosen a small case so that it'll fit under my desk.  Here's what I'm looking at:
 
Case - Foxconn TLM624-CN300C-01 Black/ Silver Steel MicroATX Mini Tower Computer Case 300W Power Supply $39.99
http://www.newegg.com/Product/Prod [...] 6811153081
 
Motherboard - GIGABYTE GA-G31M-S2L LGA 775 Intel G31 Micro ATX Intel Motherboard $66.99
http://www.newegg.com/Product/Prod [...] 6813128078
 
Video Card - Leadtek PX9600GT GeForce 9600GT $147.99
http://www.newegg.com/Product/Prod [...] 6814122048
 
Power Supply - Thermaltake TR2 W0070RUC ATX 430W Power Supply $34.99
http://www.newegg.com/Product/Prod [...] 6817153023
 
Processor - Intel Pentium E2180 $69.99
http://www.newegg.com/Product/Prod [...] 6819116052
 
Memory - SUPER TALENT 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 $37.99
http://www.newegg.com/Product/Prod [...] 6820609027
 
Hard Drive - Western Digital Caviar SE WD1600AAJS 160GB 7200 RPM 8MB Cache SATA 3.0Gb/s Hard Drive $47.99
http://www.newegg.com/Product/Prod [...] 6822136075
 
Optical Drive - PHILIPS Black SATA DVD Burner $24.99
http://www.newegg.com/Product/Prod [...] 6827248013
 
Monitor - Acer AL1916WAbd Black 19" 5ms Widescreen LCD Monitor $169.99
http://www.newegg.com/Product/Prod [...] 6824009091
 
One worry I have is regarding the PSU.  I'm not sure it'll have enough juice to run everything.  Any feedback would be welcome.
 
Thanks

I recommend you go for a 320GB drive. These 80-160 drives are old designs.
WD3200AAKS : http://www.newegg.com/Product/Prod [...] WD3200AAKS
Your case has a cheap 300W powersupply. The Thermaltake is a bit better but I wouldn't upgrade your CPU on either.

Looks like a pretty good little setup. Sounds like that board has some overclocking potential in her . For the price thats going to be a fairly quick...

Make sure your video card and your power supply will fit inside that case. I strongly recommend that you look into getting at least a mid tower case. Small cases will give you headaches when it comes to cooling and trying to fit in a newer graphics card.

I would change out the case/PSU.  Well, PSU mostly, but a combo tends to be cheaper overall.
 
The Antec Sonata III has a good PSU and is nearly the same size as the box you've chosen.  Price is $130, so $55 more (more like $40 if you include shipping - the Sonata is free).
 
To save some of the difference, you could switch to the Gigabyte P31-S3G.  This also gives you more room for the future.
 
It gives you room for upgrades later, and a power supply that will allow you to.