[Solved] Need help choosing my first GPU???

I am looking to spend $60-$100 on a graphics card at newegg.com
This is pretty much the best game i will be running http://www.totalwar.com/empire/?t=EnglishUSA

This is the mother board i have......
http://www.gigabyte.us/Products/Mo [...] 785GM-US2H

I have picked out these GPU's they seem to be pretty good??? The second one seems to have faster speeds and its cheaper...
(is there a way you can check if the card is compatible with the MOBO or does it just need to be a PCI Ex16)
Radeon HD 4830 512MB -- $99
http://www.newegg.com/Product/Prod [...] 6814102822
Core Clock 575MHz
Memory Clock 900MHz/1800MHz
Memory Size 512MB
Memory Interface 256-bit

Radeon HD 4670 512MB -- $70
http://www.newegg.com/Product/Prod [...] 6814125244
Core Clock 750MHz
Memory Clock 2000MHz
Memory Size 512MB
Memory Interface 128-bit

Also does anyone know what the sound lvl of these GPU's are?? My computer is pretty quiet so i need a GPU to match it.. (if possible)
I play mostly strategy games..!! (controlling tons of troops and stuff like that)
resolution is 1680x1050
Right now with the on board video (ATI Radeon HD 4200)

Empire: Total war - (need more graphic power) -- Release Date: March 03, 2009
Rome: Total war - (runs OK) can have 18,000 troops in one battle without lag at med graphics -- Release Date: September 27, 2005
Blitzkrieg 2 (runs GREAT) full settings -- Release Date: February 20, 2007
Stronghold 2 (runs GREAT) full settings -- Release Date: April 19, 2005
Gettysburg (runs GREAT) full settings -- Released Date: April 28, 2005

my powesupply
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i have a 4830 in my media center its pretty quiet, im fairly confident that my 120mm fans are louder than that if you leave the fan at stock settings.

Also might want to look at the 1gb variant too its only like 2 or 3 bucks more, or at least that was the case when i got mine

The 4850 requires a single PCIE power cable and a 500W power supply. If the power supply is cheap junk he wont be able to add a good graphics card like that.