Sorry for x2 post... this one is the same as abve except a slightly better processor and a 2BG stick of RAM (Only one stick so there's still space for another) to go with it... Although it's Kingston RAM :/
However the Onboard Graphics can probably support Sims 3 on it's own so you wouldn't need the GFX card..
Edit: Just check Req, graphics support Sims3
Mobo on it's own (not the bundle):
http://www.ebuyer.com/product/152752
CPU on it's own (not the bundle):h ttp://www.ebuyer.com/product/148005
All 3 together (The Bundle):
http://www.ebuyer.com/product/167098