I'm a newbie and would appreciate your advice. I do mathematical software development, not gaming, and will not be overclocking. Below are specific questions, but please feel free to comment on anything that comes to mind.
Choice of components restricted by availability from preferred supplier and compatibility with Linux. Prices below are in South African rand (R), and roughly speaking R10 = 1US$.
CPU: Intel Socket 1155 Ivy Bridge i5 3570K Quad Core 3.4GHz CPU With Fan (price R2446)
MB: Asus P8Z77-V Intel Z77 Chipset ATX (price R2507)
Cheapest ASUS mb available from supplier. Asus actively supports Linux, Gigabyte doesn't.
RAM: Corsair CMZ16GX3M4A1600C9 Vengeance 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (price R1305)
Only 16GB set in ASUS P8Z77-V Qualified Vendors List. I tend to keep PCs for a long time, and always have to buy more RAM at some point. Seeing that it's best to use one complete set instead of combining different sets...
optical drive: Samsung SH-S223C / SH-S222BB 22x Sata Black DVDROM Writer (price R180)
HDD: Western Digital Caviar Blue 1TB Sata 6G 7200RPM 64MB Cache (price R839)
I'm tempted to buy the Caviar Black instead for the 5-year warranty (price R1064).
PSU: Corsair TX550M 550W Eps12V with Modular Cable Management PSU (price R1114)
This PSU has received good reviews, but I don't know whether 550W is enough. eXtreme Power Supply Calculator recommends about 400W (at 30% capacitor aging and with 5 fans altogether). But they also warn "The recommended total Power Supply Wattage gives you a general idea on what to look for BUT it is NOT a crucial factor in power supply selection! Total Amperage Available on the +12V Rail(s) is the most important, followed by the +5V amperage and then the +3.3V amperage."
So I'm none the wiser. 550W, 600W and 650W have been recommended to me by different people. Some 650W options are Corsair TX650M 650W Eps12V with Modular Cable Management (price R1378) and Corsair HX650W Gold Certified Eps12V Modular Cable Management 650W (price R1443).
chassis: Zalman Z9 Plus With Windowed Side Panel (price R634)
I like the 4x USB 2 ports in front, as the ASUS mobo only provides 2x USB 2 ports in the back panel, and I'm still mainly using USB 2. Some alternatives are the Antec 100 with Window Side Panel (price R638) and the Corsair Carbide Series 300R (price R751).
They all come with two case fans. Should I install extra case fans?
graphics card: Might add graphics card in the future (e.g. Nvidia Quadro 600). Definitely only one.
SSD: Might add SSD drive in the future (e.g. Intel 180GB).
JMer806, I want a CPU with integrated Intel HD 4000 graphics, and the i5 3570K is the only non-i7 CPU with HD 4000 graphics available from my supplier. Will only get a dedicated graphics card if it becomes necessary in future.
AMD Radeon, thanks for clarifying that 500W would be enough. I did think that 550W would be enough. It's interesting that the (5) user reviews on newegg.com about the Corsair TX550M were mostly negative. It got a total score of 9 at jonnyguru.com, and a golden award at hardwaresecrets.com.
Of the PSUs you mentioned, only the Antec HCG-520M (price R850), xFx ProSeries Core Edition 650W (price R977) and Corsair TX650W V2 (price R1253) are available from my supplier. Thanks for drawing my attention to the much better priced xFx! It got 2 golden awards, and a score of 9/10 (twice) in the technical reviews I found.
It seems crazy to buy a 650W PSU if 500W would be enough, but at the price of the xFx ...