There isn't a 3400+ for socket 939, only for socket 754 at the moment.
You can grab a 3200+ 939 for $225 and easily overclock it to 3500+ speeds. Those winchesters chips OC like champs. It is only a difference of 200mhz anyways. Plus you would be saving $124 compared to the 3500+ 939 for $359.
IMO, save cash and grab the 3000+ or 3200+ and overclock it.