There is one similar but not quite the same at www.opro.com this is the one i have. I searched for the same one as Arlovski wears for ages but didnt find It. I settled for this opro one and it is a very good gumshield in my opinion anyway.
Please search. It's been asked at least once a month. Your three choices for custom fitted guards are basicly: Opro BiteMe Gladiator The poster above mentioned the Opro version. Biteme and Gladiator both have reps on this forum. Both offer customization options. I know Biteme gets a lot of orders on the Arlovski type of guard and has a couple of options for them as well. There should be pics of all three company's guards as well in this section.
Andrei Arlovski got his from BiteMe which is a very popular and recommended company. Joe from BiteMe has just recently started posting here. As mentioned above, Gladiator and OPro are other popular choices.
Does biteme actually sell a complete replica of Arlovski's mouthpiece? All the copies I have seen are pretty lame.
The biggest with the OPros stylistically wise is that unless you're making a huge order there's a big fat "OPro" on the front. Someone actually posted a picture of their OPro fangs awhile ago. Do a search, I cbf, at work.....