yep, stick with DDr2 rams - if you need a boost in performance then OC the CPU to 3.5-3.6 Ghz using a good CPu cooler like CM Hyper 212+ though the OC will depend on your mobo.
When you overclock u generally overclock the FSB frequency.. This is the bus to which ur northbridge components (RAM,CPU) are connected. So yes, your rams will work faster too..
And abt ur original qestion..No, you wont see a significant boost.. However ull be able to OC more usng a higher frequency DDR3