Check out our Atomic PL Mounts! We actually got to help design these and they came out great. Super easy to use and very solid and safe. Those Red primes are heavy and this mount handles them like a champ. The mounts are designed to have the correct flange depth so as long as your lenses are collimated properly, you should have accurate focus marks. I also really like how easily the mount comes on and off without allen wrenches or screws.