I'd think a few times over the system you are getting if it's "for gaming", depending on what games you want to play.
What you should do is list your budget, systems you are looking at now and your location (country).
Often times people ask the wrong questions, you don't really want to know if those two are OK for gaming or which is better, you need to know what system is best for gaming in your budget.
Both of those cards are a bit low for gaming, they are not the worst things but not near being able to play demanding games on anything over Low settings and maybe even lower resolutions.