1st build graphics card question

inthecage

Honorable
Apr 12, 2012
22
0
10,510
Power Supply -Corsair Builder Series CX600 600 watt
Memory -G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 1333MHz
[???]Drive controllers -????
CD-ROM drive(s) - w/e is in emachine et1331g
Monitor - samsung 22inch can do 1080p
Keyboard - logitech wireless
Mouse - logitech g9x
VIDEO CARD - Palit GeForce GTS250 E-Green 1 GB
HARD DRIVE - 750GB 7200rpm SATA
Motherboard - BIOSTAR TA990FXE
Microprocessor - amd phenom ii 965 black edition
Case - Apevia X-TRP-RD X-TROOPER

what im not sure of is my video card
should i buy another low grade one and SLI or should i get a higher profile? also what are "drive controllers"? please help