Hy Ivan from Cozumel Mexico, I see in your profile that you have arround 40 dives and in my opinion before you get to do the Divemaster course need to get more diving under your belt, arround 100 dives is recomended before becoming a Divemaster, that way you will feel realy confortable helping divers and organizing things arround the boat and so wich is basicly a DM job.
But about starting your academics and pool secions in one place and then finishing the rest in the ocean with an other outfit sound good to me.
Make sure that they two outfits know each other so the Instructors can comment on your training and that way you can make an better course.
I am a PADI Instructor since 1988 and also a Dive Operator in Cozumel Mexico. If any question fell free to contact me.
Good luck and great dives !