k first of all bad choice on the monitor. the VX922 apparently is not good with dvds. the vx924 has a backlight leak, and both are known to have dead pixels.........read the reviews. good monitor is Viewsonic VP930B, or LG L2000C
you dont need a PhysX card.
here is a good system which will fulfill all ur needs:
CPU: AMD Opteron 165
Motherboard: DFI Lanparty UT ultra-D
Ram: this one
http://www.newegg.com/Product/Product.asp?Item=N82E16820220079
Hard Drive: 36GB Raptor
Hard drive 2: 200GB Caviar
Optical Drive, or drives: NEC 3550A
Case: Thermaltake Tsunami
PSU: Antec TruePowerII 550Watt
Video Card: eVGA 7900GT KO
Sound Card: Creative X-Fi XtremeMusic
that comes to a total of about $1500, so if u get the LG L2000C that would cost about $2100, if VP930B, about $1800, leaving a lot more for add ons.