Well you seem to have your mind set on the 4000, so why put up the other setup if you can think of four points off the top of your head why you don't want that one. All I am suggesting that it's more important what goes in your computer, not how big the monitor is. I mean yeah, it's important up to a certain extent, but there's no point in investing on a big mointor if your computer doesn't play games well. I'm not saying the 4000 won't play games well, I'm just saying that 4200 will probably play on the same par, maybe slightly less but we're talking differences of maybe 10fps, and as both will play games around 70-80 fps, then you're not going to see the difference.
Look, lets go back to the original plan for an X2. It's meant for multi-tasking and gaming, lets leave the game side of it for the minute. What you do have with the X2 is the option of running mundane tasks in the background (like virus scans, adware, spybot, disk cleanup, disk defragmenter etc) while you play a game, whereas the 4000 would struggle to play the game at all with them going on in the background. The X2 wouldn't struggle at all, and you don't have to set time apart to check your computer for all that rubbish. You can do more important things like play games
I mean the decision is yours, and yours only, but I'm not the only one to promote the X2 to you, and if you're intent on getting the 4000, so be it. I'm just trying to point out that the X2 is a better alround processor that will run games around the same, but you get all the multi-tasking abilities with it.