I think you pretty much nailed it.
The only caveat in your list of requirements I see is that the 1564 and it's stock GMA 4500HD graphics chip is weaker than you might like playing Sims3. It's only at the lowest graphics detail setting that you'd get smooth game play.
Getting the 1564 model with the Mobility Radeon HD 4330 upgrade will fix that - allowing medium graphics quality settings.Sims3 on Laptop graphics cards
The top of the line 1564 with it's Core i5-520M and Mobility Radeon HD 5450 might be a good bet to cover the future versions.