Why don't you start building your initial round via trad? This way you may build a decent customer base to launch into WFP once you have some on the job experience and more importantly a bunch of loyal and patient customers. You'll also have minimal overheads and set up costs. Should things then not work out you'll not take too much of a hit.
Whatever you do, don't do this. It is advice which is ten years out of date. The trolley system and pole need not cost you more than a few hundred pounds to put together.
It's like taking milk churns off the loading platform, putting them on the floor and lifting them onto the back of the wagon.