Hi Dear!
I made the same thing that you want but it uses a single motor. I uploaded the project on my website with free source code and circuit diagram. Please see the project and its video http : // www . microcontroller-project . com / stepper-motor-controlled-with-hc06-bluetooth-module . html
I can modify the upper project for you. Its an easy task for me. I have all the hardware stuff with me.
About Me:
I am a professional PCB and Circuit Designer. I designed many circuits and their PCB's. I also do programming of microcontrollers and their interfacing with different electronics components. I have experience with Pic,8051, Arduino, Atmel etc microcontrollers.
You can see my work and experience on my profile and website.... I made many end products from component selection to circuit design and pcb printing, i have gone through all steps... I also have links in china for the rapid production of product in quantity or samples....
I am Running a Website Under the name www . microcontroller-project . com You can see my work on it. Their are lot of Projects on it using different microcontrollers.
Feel free to discuss more about the project with me. I am not annoying only talk about the project, no extra messages.
Regards
Usman Ali