Nobody but you can really answer your question but I can help you start looking in the right place, then you really need to research all your options, if you have lots of money you can just go buy the best and forget, but that isnt usually case for most of us.
I assume from reading your post you haven't bought a laptop yet, here are two options that will give you what you need (just copy and paste the links to your address bar if their not active links.) http://dealnews.com/lw/artclick.html?2,620389,2375847
This is a Sony VIAO, its pretty afforadable, but mostly it has the option to get a NVIDIA GeForce 640M graphics card. this is a good mid level card should do most of what you want at a decent price, but remember its an option it makes this $640 laptop a $740 laptop, and if your willing to spend a little more you can get this....http://dealnews.com/lw/artclick.html?2,620389,2375848
This is an Alienware, it has the NVIDIA GeForce 650M card with optimus this is a much better card but may be more then you need, its just worth looking at because its only slightly more money.