Maybe in the contract it could state how many people are ahead of you, say like "There are 4 people ahead of you, with an average of 3 months per build".
I dont know, just a thought.
The lesson is to do your due diligence and ask questions, lots of questions, just like that one and many others that have been suggested in this thread.
However, putting all those answers into the most "ironclad" contract developed by the most expensive lawyers in all the land likely wouldn't change Mr. Halo's actions one iota. Companies that are struggling, poorly managed, etc, do this sort of thing all the time, and for much higher stakes than this, with contracts as thick as a small city's phonebook. I've personally had a client that pre-paid $800K on $2.3 million of equipment for a facility, only to have the company take the money, fritter it away trying to deliver on promises to others in line ahead of us, and then running into bankruptcy when the coffers ran dry and before delivering my client's equipment order. Now, we had a more than adequate contract, and pursued all our remedies aggressively at the first hint of BS, and guess where that got us? We're in line with other creditors in BK court, with no hope of ever squeezing any blood from that stone. Our lesson: no more pre-pay up front. Progress payments only when suitable proof of progress.
Fact is, you win a legal battle under the present situation just as easy as you would win if you had the most marvelous contract in all the world. The fact remains under either scenario, your legal remedies under the circumstances are poor, at best.
IMHO, there are only two contract terms that are paramount to negotiate when dealing with a custom builder, each of which can be suitably negotiated in an oral contract:
(1) The Deposit. For a custom build, never pay in full at the time of order. If the builder doesn't already require something less, then negotiate something less or go find another builder.
(2) The Method of Payment. Make sure they take AMEX or PayPal, and use the one that will protect you the longest, and let those folks fight your battle. Make sure you know the window in which they will agree to do so. At the first hint of something going astray, drop the hammer. Sorry if I missed it, but have you looked into whether or not you have any recourse through the company you used to pay them? The chances are probably not great given the elapsed time, but I sure as heck would have run that to ground if you haven't.