I think you would be surprised how many are compatible, the better question is how many are not compatible! However, there are a few considerations you could make in your build in regards to the GTX 570:
1) Does your case have the clearance for the card? - this a problem that most of us have ran into more often than not.
2) The GTX 570 uses PCI-X 2.0, as mentioned above almost every modern board for a gaming build ranging from cheap to expensive will likely support this card.
3) Make sure power supply can push the card (500-550 Watt minimum) and have room to expand if you want to use SLi (750-800 Watt minimum), such as have multiple 6/8 pin power connections for the card.
4) If you want to expand to more than one GTX 570, your new mobo will need to be SLi ready, so this will typically be an Intel/Nvidia type setup.
If I'm telling you things you already know I apologize, anyways, hopefully that is helpful.
If you are looking for more specifics in your board, just let me know and I could try to make some recommendations
Thank you for the information. This is actually going to be my first custom pc build so any information is well received. I am planning to use a XFX P1-550S-XXB9 PRO550W Core Edition Power Supply. Do you think this will be enough to "push the card".
Also what do you mean by making sure the case has clearance for the card? Sorry for all of the questions its just that I am a newbie to all of this computer jargon.
That power supply should be just fine, XFX is good brand and the "80" plus rating and japanese capacitors that is associated with it helps to ensure (at least a little bit) its quality.
As far as clearance in regards to the case, I'm actually talking about how the card fits in the case that you have. Some of these gaming cards are quite long, and in some smaller form factor and mid-tower cases, the fit can be quite tight which can lead to a few issues:
1) The card doesn't fit at all and you cannot put in the case.
2) It restricts airflow to the card's fan(s) and can cause it to overheat
This card is 10.5 inches long, so typically you want to measure the back portion of the case (where you would actually seat/screw in the card) and the area where the hard drive/peripherial bays are located (or whatever else lies directly in-line with the card). The good thing is that the power connections for this card are on top of the card and not on the end, which helps in this situation.
This is one reason why I switched to full-tower cases because of airflow, clearance, cable management, and ease of installation - the downside being they are big and can be freaking heavy. If you are wanting to LAN a lot, you may or may not want a full-tower (though I would still recommend it).