If you have access to liquid nitrogen you can just buy some YBCO tablets, a strip of flexible permanent magnet (looks like plastic but contains enough metal to be ferromagnetic) and some coils to drive the train forward. Thats really all you need to build a superconducting maglev model train.
At the university where I used to work we used a setup like this to demonstrate superconductivity (and for the more advanced students the properties of type II superconductors).