A:Answer you will need to look at the motherboard specs to find out what types of slot/s it has, and what version of communications ie PCIX8,, PCI X16,, ETC..
will need to make sure there are drivers available for version of windows you are running,
as to if one is better than the other, would have to have specs for each to compare, many,, many features to compare, one might have faster screen rates, but lower memory, or resolution rates, CPU on card speeds,, can even get down to chip sets on card..
both your questions can only be answered by providing more info,, you need to research and learn,,
have fun.