If you want to get rid of the cabinets, you can sheetrock over the openings and remove the trim. Then you should be able to find bifold doors to fit the closets.

You have no dimensions....... They are each 36 inches wide?

I would bust open the entire mess, add header, and make well thought out reach in closets. You probably have a potential eight feet or more of useful storage

Much depends dimension, door style from simple swing on a ball catch to sliding, to bi fold to whether you want them separate etc. and of course budget.

What is INSIDE and is there a reason for the separation. Such as ducting......who knows what?

Shown with no doors.......for interior only.

Budget for closets? Will you be flipping the house or keeping for your own residence?

Keep the above door storage and just get new bifold doors. You can trim to fit. Paint everything the same.