Is this all compatible with each other?

POWERCOLOR Radeon HD 4870 AX4870 512MD5 Video Card
http://www.newegg.com/Product/Produc...82E16814131140

Broadway Com Corp Okia-black-650 650W Power Supply
http://www.newegg.com/Product/Produc...82E16817162014

Rosewill R6426-P BK ATX Mid Tower Computer Case
http://www.newegg.com/Product/Produc...82E16811147068

AMD Phenom II X2 545 3.0GHz Socket AM3 80W Dual-Core Processor
http://www.newegg.com/Product/Produc...82E16819103694

SAMSUNG DVD Burner Black SATA Model SH-S223L LightScribe Support
http://www.newegg.com/Product/Produc...82E16827151188

BIOSTAR TA790GXE 128M ATX AMD Motherboard
http://www.newegg.com/Product/Produc...82E16813138146

Crucial 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory
http://www.newegg.com/Product/Produc...82E16820148163

Western Digital Caviar Blue 320GB 3.5" SATA 3.0Gb/s Internal Hard Drive
http://www.newegg.com/Product/Produc...82E16822136098

Grand Total: $538.90 (including some accessories I need. That + Shipping = ~600$)

I might be able to get a new PC soon and settled on these parts after spending hours and hours on Newegg.

I know the board is CrossFireX Ready(Right? Lol), and I have 1 card. In the future when games are more demanding I'd like to add a second.

I'll be blunt: the Power Supply is junk - don't buy that brand in general, and no matter the brand name the specs on that PSU are not good.

You want to get a PSU that has at least 40 amps on the 12 volt rail (multiple 12V+ rails are good too). That one you selected has a measly 24 amps.... it says 650 watts but any system that draws close to that many watts will fry the 12volt rail. For $55 you can get a far better PSU.
This one will kick the other PSU down the street, is $50 after MIR, and is a reputable brand name product

http://www.newegg.com/Product/Produc...82E16817341017

Other than that your build looks good.

I agree with Elder. For some odd reason, the Broadway unit puts most of it's amperage capability into the +5volt line, but you need the power in the +12volt circuit(s).

Will this PSU

http://www.newegg.com/Product/Produc...82E16817339025
OR
http://www.newegg.com/Product/Produc...82E16817339009

work fine with the video card? I'm just trying to see how cheap I can go because my budget is lower than I thought.

Edit: Corrected a link, posted wrong one.