I wish my monitor could refresh at 144mhz. By the way it refreshes in Hz not mhz. 1,000,000 hz is 1 mhz. I have no experience in 3D gaming so I can't help you in this topic.
Considering you're currently on a 19" 1440*900 res monitor there are things you have to consider beyond just choosing between a 144Hz 1080p 3D monitor and a 1440p monitor. You have to consider what your computer can handle. If you're running 3D you're going to have a major performance hit since you're now rendering a frame per eye rather than the single frames you were before. You'll also have to consider you'll see a performance hit if you choose the 1440p monitor since it's a higher resolution and thus has close to 3 times as many pixels. Your 1440*900 display has 1,296,000 pixels, a 1080p display has 2,073,600, and a 1440p display has 3,686,400. The 144Hz monitor will be superior to a 60Hz monitor in terms of motion, but only if your hardware can keep things at higher framerates (say 100+ fps).
With all these things in mind, I really have to ask: what are your specs?
To be quite honest about 3D gaming, I find it to be pretty lame and also a failed market that has followed in the footsteps of the virtual boy, the idea in itself sounds like it would be awesome. however its really not worth the money, headaches, or lack of current generation support. something better will come out eventually here so what im saying is I would just save the money and not go with the 3D.
as I stated before I personally see 3D as a novelty item that isn't worth the money or time, but that is just my opinion, if you have the option to go somewhere and demo 3D I wouldn't be shocked if you came to the same opinion honestly.
Get a 1440p monitor from Newegg. They now sell those Korean ones. If you're planning on keeping this monitor for a while, I'd really recommend going 1440p. The extra desktop real estate is really nice. Everyone is going to be upgrading to 1440p/4K in the next five years and you don't want to be left behind, do you?
Also, the 3GB of GDDR5 in that 780 won't be used completely for 1080p gaming.