iMacs by default are dual monitor systems. You can take a standard VGA monitor and plug it into an iMac. So screw off the LCD and plug in the VGA monitor in the closet and go back to work.
By standard VGA monitor, do you mean a "Video Graphics Array" monitor? Wasn't this standard created by, gasp!, the enemy, IBM, the creator of the PC?
I'm just yankin' your chain.
Personally, I think this whole Mac vs. PC thing is no different than a Ford vs. Chevy argument. And is about as mature.
FRegards,
dan