Best option??

Sli does not reduce the lifespan of the card.

Get two 8800GTs or 9800GTs 512mb. The 8800/9800GT are powerful and inexpensive cards.

Don't get the 1GB because none of them are powerful enough to use all that memory.
See if you can buy from Newegg.

9800GT should be ~$110-120 USD
9600GT should be ~$70-80 USD

 
Newegg will not ship to Mexico last time I checked.

As for the question, 9800GT is the best of those listed, however the 1GB version is a waste as blue has said.
 
My idea is to use the motherboard for sli, I have a budget of 220 for an ATI video card or envidia or two 9600 GT is what I was going to buy.
excuse my English but I am using a translator
 
Thanks for your comments is that the problem here in mexico are any of these cards in more than 300