Tom's bench at the 1280x1024 did not have AF or AA enabled, so you should be able to gain some FPS using the same settings but at a smaller resolution. Your smaller resolution as compared to the bench will help in gaining FPS over what the bench reports, provided that you use the same settings. Enabling AF and/or AA will impact your FPS, but 95FPS is overkill.
Guru did state that a 9600 was able to play the game at 1980x1200 @ 31 FPS, and the the 9800GTX+ was pulling 43FPS. So you should be looking at more than 43FPS while playing at your resolution.
Bottom line - the GTS 250 will play this game at your resolution with AF and/or AA enabled (though I don't know what the max levels are for each setting, something you're going to have to play around with.)