Back a number of years ago we had a similar situation and we had to find our own financing for clients - we found that if there was a hardware purchase as well, some of the lenders were willing to add the software and some of the consulting services as well.
Challenge was always managing that block of time - when it ran out - the client still did not want to have pay - but that is a whole other challenge.
So, I think that self financing is the only option - someone else may know different.
