hi,
i have read all your problem.
i see you need to fix some code on your web,add some feature and add a page too.
for the image zoom, i'm planning using pop up box.
for the coupon, i can generate unique code.
and other thing we will discuss if you contact me.
i'm well experienced with php and mysql, also on client side jquery and css.
i can do this job for you.
i can start anytime and work full time for your project.
feel free to contact and ask me.
thank you,
Surya Wono