Sprint Touch and earpiece question..

I am highly thinking of buying this phone. What I would like to know is with
the voice dialing option the phone comes with, will I be able to speak into
my bluetooth earpiece and say the name of the contact trained or do I have
to use the phone itself? I have a 700p that I love but what I don't like
about it is that I can't use the earpiece to just say the name of the
contact I want and it dials it. I have another phone by LG that does exactly
that and I use it for work. I want to dump both phones and just have one but
for the work I do, I do a lot of driving and I need to be able to just say a
name into my bluetooth headset without hand dialing. Thanks!!