H4 Visa Appointment in case of change of Employer

I have H1B visa dropbox appointment with current employer this month. I have also got new job offer and my new employer told me that they will begin my h1b transfer process after i reach to usa with visa stamp of current employer.

I wanted to start process of H4 visa for my spouse and get the Visa appointment date.( By filling DS 160 with details of My current employer).
I will get new petition once my h1b transfer process completes. so is it possible to keep the H4 visa appointment as is and fill the new DS 160 form with my new Petition and scrap the old Ds160.

Yes. Once you submit the updated DS160 call VFS and provide them the the new DS160 number. Have the H4 carry both old and new DS160 confirmation page to their appointment.