Enterprise level "payday loans"?

Hi guys,

A startup I am working on is signing our first BIG customer. Exciting news and all, but the timeline between signing, integration, and ultimate payment runs past our remaining runway :S

We are beginning another small investment round, but I'm looking for other possible short-term stop-gaps (failing to prepare is preparing to fail!)

On that note, I'm wondering if there are any services that provide, I guess the best term would be, payday loans for startups? With the successful signature of this customer, we'll be good for the money, but we have to keep the lights on before the end of the first billing cycle.

Thoughts and feedback very much appreciated!