Few things...
1. I still run my old Profile carbon flat bar. No flex, but it does do a fine job of no transmitting as much vibration.
2. Your fork choice will help some. I run a Ti rigid fork which is fairly flexy. It made a major difference.
3. Magnesium... great for killing vibration. I run an older Easton Mg stem.
4. Bar sweep... the older I get, the more sweep I like. I am gutting out running a 2deg sweep though. On my single-speed I run 9deg and my hands are much more comfy.
Yea, you could go with a suspension fork, but really it's more about the fit of your bike and hand position. The suspension will help on mid-level stuff, but on the road, not a huge amount. Go to an LBS and get fitted.