It's extremely difficult to get a low-interest bank loan right now, even with a great business plan. I know this isn't a "good" idea, but you can take out a cash advance sometimes on your personal credit cards. It is high interest, but you really aren't borrowing that much and you hopefully can pay it off quickly. Also, you could just use a personal credit card for the items you need. I co-own a business and sometimes you have to be creative like this in this economy to get working capital. It sucks but sometimes it's the only way to do it.
I, too, have worked with the SBA's SCORE and while they helped me a lot with my business plan, they did squat for me as far as helping me get a loan. There just aren't any banks willing to take many risks right now.