why do you need them? Are you running a power adder? Know that the quality of 6AL boxes has suffered greatly over the last 5-10 years since they offshored production. Personally, I would either get a Crane Digital ignition or a Holley unit.
If you are dead set on the MSD brand, there are tons for sale on the Corral, yellow bullet. Craig list,.... for a reason. New I'd go with Summit.