You can certainly try with just the DB4e. It has *some* hi-vhf capabilities. AD doesn't advertise that, because they didn't design it for hi-vhf, but it does.
If it turns out to not be enough you can add a dedicated hi-vhf antenna at a later date.
I agree with No Static. WBAL is a better NBC option than WRC (although CoziTV is fairly cool)
If you are considering a pre-amp, look at an
RCA tvpramp1r
It has separate vhf & uhf inputs, or it can also operate in combined mode