Hardware suggestions for an inspiron 530s

i have a dell inspiron 530s, its a slim tower desktop, im wondering what cards i could get that would work with it, and as well as any psu's. low profile cards being the main ones im looking for. open to all suggestions. all i really want to do is play arma on decent settings, or even arma 2. im not looking for ultra realism, or being able to see five miles away, view distance isnt a big issue for me right now, i just want to play this game with a few friends, but i dont want to be working with the bare minimum if that makes any sense. thanks everyone. also, i've got a budget to work with, of about $300. any opinions about the cheap $60-$80 low profile 54XX series cards from ati? i've seen a guy on youtube running cryisis in a 530s with a low profile card. thanks comrades!

---------- Post added at 16:40 ---------- Previous post was at 15:42 ----------

Operating System: Windows Vistaâ„¢ Home Premium (6.0, Build 6002) Service Pack 2 (6002.vistasp2_gdr.110617-0336)

Language: English (Regional Setting: English)

System Manufacturer: Dell Inc.

System Model: Inspiron 530s

BIOS: Phoenix - AwardBIOS v6.00PG

Processor: Pentium® Dual-Core CPU E5200 @ 2.50GHz (2 CPUs), ~2.5GHz

Memory: 4084MB RAM

Page File: 2740MB used, 5640MB available

Windows Dir: C:\Windows

DirectX Version: DirectX 11

DX Setup Parameters: Not found

DxDiag Version: 7.00.6002.18107 32bit Unicode

Display Devices

---------------

Card name: Intel® G33/G31 Express Chipset Family

Manufacturer: Intel Corporation

Chip type: Intel® GMA 3100

DAC type: Internal

Device Key: Enum\PCI\VEN_8086&DEV_29C2&SUBSYS_020D1028&REV_02

Display Memory: 286 MB

Dedicated Memory: 0 MB

Shared Memory: 286 MB

Current Mode: 1024 x 768 (32 bit) (60Hz)

if any of that helps. i think its a pci-e mobo too. cant recall.

ok, looking at buying a radeon 6670 low profile card. for around $100 it runs alot of the modern games so hopefully it will at least run arma/arma2