Good choice on the thermal compound.. It's fucking pricey for how much you get but there really is a difference between using arctic silver 5 and regular white pasty shit.
Like someone else said only bad choice I see is the hard drive. Get an SSD for OS and a mechanical for everything else. 30gb is more than enough from OS and programs from what I read. I went 40gb to be safe, but am using only 21 for OS and programs..
erm, from what you read? might want to add steam to your readings next time
30g isn't gonna cut it for most gamers, of course, you could set your game DIRs separately .. but .. who does that?? (epic fast drive, send your game files offshores wheee...) Page file??
Not saying any of these are worth buying, purely a price comparison for .au .. so it really means nothing for you
Corsair Force SATA3 Series 60GB 2.5 SSD Instock $115.00
OCZ Agility 3 60G SATA3 SSD  Instock $119.00
OCZ 60G Vertex Plus SSD Instock $79.00
OCZ 60G Vertex III Series SSD Instock $139.00
Intel X25-M 80GB 2.5 MLC Solid State Hard Drive 3.5"Kit Instock $161.50
OCZ 480G Vertex III Series SSD PreorderETA $1289.00
Do think about your SSD size though, it's not something you would want to cheap out on, try spend about as much as you would've for the spinning HDD, consider any extra HDD space as a down the line upgrade.