It feels like a catch-22, isn`t it? Need money first to get money.
1) Will $140,000 will just get you to Release 1 or just a prototype? What about follow-up releases, maintenance, ongoing support etc.etc.
2) Would you consider an investment "in kind"? Meaning, maybe instead of paying someone $140K to build "it", you can take one a partner (either an individuals, firm or group of individuals) to build it. Remember for every Bill Gates, there is always a Paul Allen right next to him. You can always pitch it to potential technology partners (these are the firms that you will have an interest in seeing you succeed for potential business for them). Have you looked at grants from schools, government, etc. etc.
3) Usually, friends and family would be a good source to get seed money. Most of the time, this would be in a form of a loan covertible to equity if they so choose (called a debenture).
4) If you have a clear line of sight on Revenue (or Profit), then leveraging your good credit, home equity, credit cards etc. etc. would be a resort. This is RISKY but it has been done.
5) At this phase, it sounds like it`s too early to hit the private equity/VC people. Unless you want to end up working for them.
Good luck.