(First post, hope I got this right :D)
For me, my primary physical therapist scheduled a representative from Numotion to come to one of my appointments and explain my options to my mom and me. From there we decided to order a scooter which she and my therapist handled almost the entire process. My therapist also handled ordering my orthotics and shoes. I think having the aid of my clinic made the process easy and stress-free. If I had to do it without their help I would probably try to get my primary doctor help me with the process.