What kind of DI are you looking for? You have two major players in Own Occupation for the most part, Union Central and Guardian. The others are good but be real careful on how they define Occupation, it varies between companies.
I forgot, wrote the last reply kind of quickly. Don't forget Standard, so you have Guardian, Standard and Union Central. Forget about the others if you want the best contractual language for Own Occupation. At least IMHO.