Suspension Design

As a senior project at my school, we are designing a personal mobility device for the elderly. A suspension system is a must have as it must track smoothly through city streets. The basic calculations have been done and we have acquired the necessary spring rates, damping coeff, etc. However, we need to design and physically build a working prototype of this vehicle by the end of this semester. We have scrapped several designs in the past due to difficulties in manufacturing. Question is, where can we acquire suspension components to fit our calculations? I've looked up bike and trike suspension components and we weren't able to acquire the technical specifications aside from the weight rating. Can someone help me find a viable manufacturing solution for a suspension system? We prefer some sort of a coilover system but we'll take anything thats possible at this point. Thanks.

Have you already looked at custom suspension manufacturers like Aldan American, bcracingusa or hyperco?