Getting a new tag made is very simple. There are two reputable companies doing them. www.datatags.com and www.trimtags.com.

HOWEVER
Getting a correct tag made is 100% IMPOSSIBLE without the broadcast sheet or original fender tag. There are two bits of info on every tag that match the broadcast sheet and they are the scheduled build date and the vehicle order number.

If you don't have the original information, you can always have a little fun by getting a tag made that matches your car and just "make up" to two numbers mentioned above.
HOWEVER
Don't think that you'll be able to pass that tag off as original, because there are plenty of people who keep track of this type of info and will be able to tell if your numbers don't jive with the VIN sequence number