decided on iMac - help on which one pls

I have decided that the best thing for my wife would be an iMac, it just makes sense: she'll use it may be once or twice a month to do some work from home and that is check emails, review documents (Word) - she is a lawyer!! - and possibly some web surfing (very little I would think).

Anyway the iMac seems good as it takes minimal amount of place, no cluttering etc. Now however the only undecision I have (and it may sound stupid given her usage) is whether I should consider the 17". Normally the 1Ghz, 15" would be perfect, the only doubt I have is for the graphic card which seems to be an old piece of c***p on the 15". You know, even surfing the web nowdays requires some graphic performance ! Anyhow, the graphic card would be the only reason for me to get the 17". No need for larger screen and no need for the unsignificant .25Mhz faster processor. Sure my son would probably use it a little for games (I prefer not to install that stuff on my powermac) but he is 2.5yo so I doubt he'll play any demanding games graphic wise.

What would you guys think ? am I overthinking about this ?

BTW: where would you get it ? it'd nice to avoid Apple just to save taxes, I mean, not major but hey....

thx

thx guys.
As I was writing my post earlier today it did occur to me that the eMac might be the answer. So, I have decided I am definetely going to ask her if she likes it: if she does I will get that. If not, I am not sure.