I bought the combo from tigerdirect. I really like the deal, and I easily have the 3400+ running at 3800 speeds. However tiger direct does not come with a heatsink. The rebates also take a while as well.
The CPU from newegg will be a better overclocker most likely if you invest in a new heatsink though.
Also please be advised, that the 3400+ and 3500+ are the same speed (actually the 3400+ is a tad faster)
Make sure to leave a shipping note when ordering for UPS to require a signature and not drop off the package with noone home.