What options do I have if a supplier breaches the contract after taking my upfront payment?

If the contract is well drafted, all of the answers to your questions will be contained in the contract itself – enforcement methods (trial vs. arbitration), damages recovery (caps, methodology), penalties (if any), etc. Without seeing the contract, no one will be able to give you definitive answers to any of those. I'm happy to review and give you some feedback regarding your options. I do not handle any litigation matters, though, so if you moved forward beyond sending a demand letter, I'd have to refer you to someone.