Hi and welcome to the forum, conversions can be done on twin opening and there are pro's and cons. (Greater ventilation with a twin door.)
I believe that the interior profile is slightly different as the pillars are thicker to allow for extra strength in having two big holes in each side.
Kombi's come in single opening also which is more commonly used in conversions.
Have a look at layouts your after and see if a twin door will work for you or if a single would be better.
Good luck...