ViewSonic NextVision N4, N5 or N6?

[hyn]

I am looking to purchase one of these to hook up my PS2 to my 21" LCD display. I see that the N4 is only capable of 1024x while N6 can do 1280x.
What does this mean for PS2 and HD gaming (PS3, Xbox360)?

Is N6 the way to go if I wanted future proof gaming on my 21" LCD display?
The display is 1920x1200 natural resolution.

Also does the N4/5/6 have built-in scaling features so that the image gets blown up to 1600x1200 for example? I don't want it to strech the image and do 1920x1200.

[hyn]

Apparently this box only outputs VGA... my 21" LCD takes DVI only.
VGA to DVI converters apparently cost $300+... is there a cheaper alternative to gaming on DVI LCD displays?