It seems like anytime I have needed something all you have to do is ask. It is amazing what local businesses and people will do to help out if you just ask. Another idea would be to search out local sororities or fraternities to see if they can help. There are more than just college sororities and fraternities, but there are a TON of philanthropic ones set up. Here is an example http://www.thetaepsilon.com/ Search for ones like this, and others that are more local to your area. They are always willing to help out, and can be a great resource if they can't.
The best way to solicit I have found is to start with a letter explaining what you need, how much, and why you need it. Make sure at the end of the letter you give them a way to take action. For instance, a "please call me at ..." or something like that. Then about a 4-7 days after you send it out make sure to make a follow up call. It will be easy to start the conversation because you already have the letter to talk about. Most people are too busy, and just won't call back or make the effort. But if you call them, they are likely to help out. If you send it to a sorority or fraternity, I'd wait a little longer to call, because some of them only hold a meeting once a month.
You will be amazed at 1- Who you can find to help with your facility, and 2- How many people are willing to help. If you contact smaller organizations and businesses you will likely get a better response. Trying Walmart is good too, but they get so many requests per year, that if they have already reached their budget they won't be able to donate.
Hope that helps-
Amy
http://thealist.squarespace.com