Need Help On New System.

Ci7 motherboards usually use triple channel RAM .

I'd buy any motherboard EXCEPT one made by intel . Chances are they dont give you BIOS options

Gigabyte and ASUS instead , and 3 x 2 gb triple channel memory

Triple chanel memory on the i7's needs 3 sticks of ram to work, so either 3x1gb or 3x2gb is what you should go for to get optimal memory bandwidth. Intel mobo's do not give you the overclocking bios options that make the i7 so good (usually, the upper echelon Intel ones might, but the features on those mobo's come standard on much cheaper ones from a third party manufacturer). Get an ASUS P6T Deluxe v2 or Gigabyte GA-EX58-UD5 (or P6T / GA-EX58-UD4P if you can't afford those other ones).

Don't get a sound card until you try out onboard sound, chances are you won't need the sound card since most onboard sound is pretty decent these days.

The GPU/Monitor are closely related things. If you get a higher resolution monitor, then you need a more powerful GPU. If you want to get a GTX 285, then you need to get at least a 1650x1080 res monitor otherwise you will be wasting your money on that GPU.

PSU: Corsair 850tx if you plan to SLI later with 2 GTX 285's, otherwise a Corsair 650tx for just one GPU

Case: This depends on what you like more than anything. Do you want lots of lights and windows to look inside? Do you want it to be quiet? Do you want a simple, sleek, refined look or a flashy look? Here are some good cases to look at, these all have my personal seal of approval for room and excellent cooling:
Antec 1200
Antec 900
Antec P182
CoolerMaster Cosmos series
CoolerMaster Haf 932
CoolerMaster 830 Stacker
CoolerMaster Storm Sniper
CoolerMaster RC-690
Thermaltake Amour+
Thermaltake V9
Thermaltake Speedo
Thermaltake ElementS

Logitech always gets my business when it comes to speakers. I have no idea what you want out of them so cannot give a recommendation without more info.

I have no idea what the conversion rate of SGD to USD is so that $2600 figure is useless to me, as well to most of the other users here on the forum I think unless you give us a site to look at to purchase from or a conversion rate to work off of.

Also what exactly is this PC for? Primarily gaming? Video editing? or just an all-around PC?

Something also to keep as a note is that you should not use ram sticks that have voltages higher than 1.65v. So a lot of dual channel ddr3 modules are unsafe for x58 boards and i7's.

@motaku's comments,

I would say just go with a 64 bit OS. If you picked up a gtx 285 and had 3gbs of ram then you'd go over what your 32 bit OS could handle already. I'd scratch the 32 bit OS from the start on this one.

Do you guys think i have enough o.o?Anyway here's my latest update.
My budget now is $3.5k SGD

Intel Core i7 920 - $432
NVIDIA GeForce GTX 285 - $544
Creative X-Fi Titanium Fatal1ty Champion Series - $299
Corsair Core i7 Dominator 6GB PC12800 DDR3 RAM - Tri Channel, 1600MHz, 6144MB (3 x 2048MB), DHX - $267
ASUS P6T Deluxe LGA1366 Intel X58 DDR3-1600 ATX Motherboard - $551
Western Digital Caviar Black 1 TB Bulk/OEM Hard Drive 3.5 Inch, 32 MB Cache, 7200 RPM SATA II WD1001FALS - $180
SAMSUNG 2233SW 21.5 FULL HD LCD Monitor - $248
Corsair HX620 - $230
Ultra-120 eXtreme 1366 RT - $264
Creative Inspire T6200 - $149 ( Still Considering )
Antec Twelve Hundred ATX 12 Drive Bays 2xUSB 2.0 eSATA Audio Mid Tower Case - $274
Razer Keyboard Arctosa Silver Edition - $80
Razer Destructor - White - $64
Razer Lachesis - $128
Might want to consider eVGA 260GTX SC

TOTAL: $3556

I just got the price from amazon.com only.

why get the P6T Deluxe V2 o.o? its better?