If you want used, I know there are several 67 Plymouth B-Bodies at Clay Kossuth's place (Catawissa, MO) being parted out that still had taillight as of a few months ago.

His email is maxattac1@aol.com
PM me if you want his phone number.
I'm pretty sure that they'll ship out parts.
I know that they deliver parts to races around the country too.

Depending on which repro taillights you're talking about there may be issues.
I can't say from personal experience.

As far as new, BEA Parts only show the GTX version, their parts are usually pretty nice.

Layson's makes both versions for a 67, but personally when I've looked at them at the Nats I wasn't impressed with the quality. Just an opinion.