Using an external monitor with a laptop -- resolution? Which cables?

Hi there,

I am looking at buying a massive 23.6" screen on sale from Newegg for about 150 bucks (free shipping), except that it would be a display for a laptop computer, not a desktop.

The laptop I have is an Asus K50-ID, equipped with a GT 320M (Nvidia doesn't have a product page for it, but I am fairly sure after a year that this is about right. The laptop is equipped with a 15-pin DE-15 VGA socket and an HDMI port. Its max resolution is 1366X768.

The monitor is an Acer X233HZBD. I guess now's the time for you guys to tell me how good the monitor itself is. It supports DVI and D-Sub inputs.

Before I commit to purchasing, I would like to ask some quick questions.

1.) Will the computer be able to support a higher resolution? Or would I be better off buying the other monitor on sale, a 19" one? For that matter, does rendering the image on the monitor affect performance at all? I use this computer primarily to game (it is a college kid's laptop, though), and if the image would look like crap (because I have to use lower resolution or because I have to reduce non-resolution settings in my games (effects, etc.) to play), I guess I'd rather just use the computer's built-in monitor.

2.) Which is better/would produce a better image/higher resolution, using the RGB connectors outright or buying an HDMI to DVI connector and using that? Want to know so I can order the adapter/connector/whatever with the monitor so I'm not waiting for a while.

Before you guys go off and say "WHY WOULD YOU USE A MONITOR WITH A LAPTOP WHAT'S THE POINT", well, I kind of want to build a desktop either this year or next year, and it would be nice to grab a good-sized monitor while it's cheap. Again, if it's cheap for a reason, let me know.

Thanks for your help!