No doubt a suspended car will be better on all tracks, more consistent and easier to stop. I would not go for a typical 4 link car, I would go for a Swingarm suspension (bottom bars of suspension tied together). You get no chassis/body roll with the swingarm at the big end. I like the 2 shocks but lots have great luck with the single shock so either way would be good.
The suspended car may weigh a little more but if you plan on racing td the weight usually isnt huge its the motor that matters.