modify base net (VGG) of ssd

[PythonImageDeveloper]

Hi . Q1: i want to modify the base net of ssd for my purpose . is this possible for your code ? i want to examine iception v1 , densenet , mobilenet , ... instead of vgg . is this possible ? what do i do ? where do i define your base model ?
Q2 : dose your ssd model different from the original model ? Q3: what's your os , cuda , cudnn , tensorflow , GTX ? Q4: if i want to fine-tune this code for detection Pedestrian , car , cyclist , what do i do ? please help me . thanks.