Have a frank conversation with your employer about your concerns. "I've done all this work, I haven't been paid, you don't seem to have any money, can you guarantee that I will be paid when this is all said and done?" If "yes", "Great. I'd like 1/2 or 1/3 or 1/4 now (for however much work you've already done) and the rest on full delivery. If "no", "Ok, well I'm going to have to put this project on hold until your funding comes through. I'll send you a bill for the work I've already done." If it's a lot of money you could immediate file a suit to get a claim on any assets they may have at hand.

I've paid contractors a number of ways: 0 up front, 100% on delivery; 0 up front, 50% at 1/2 way, 50% at final delivery; and 10% up front, 40% at the 1/2 way point, and the other 50% at final delivery.

0 up front, 100% on delivery has been the most common for me because I contract out relatively small projects ($500-$1000 range)