Good Step Up From 560Ti - Xplane And Maybe Prepar3D?

Hi, i7 3770k, 32 gigs ram, 560 GTX ti 1 gig video. Single monitor resolution 1680 x 1050

I'm looking to maximize my xplane experience and wondered would a good step up would be. I might get Prepar3d in the future also.I've searched and read alot of posts, but would appreciate some recommendations. Thanks in advance.

I'm guessing 4Gig Vram is more future proof, but what are the specific card recommendations? and what are the most relevant specs? Memory bandwidth, texel rate, pixel rate?

I'm willing to go as high as $400, but no more than that.

So far I've seen recommendations for a GTX 760 or 770, so something like this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130948

or this?

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130949

according to this site a jump to the 770GTX would blow my current card away:

http://www.hwcompare.com/14660/geforce-gtx-560-ti-vs-geforce-gtx-770/