Other than SBIR/STTR/VC, I wonder what other funding sources are
available for researchers in Small Businesses and what are the
proposal acceptance rates respectively.

Reference to existing reports/reviews regarding this topic is qualified.

There is the ATP grant from NIST, which awards upward of $1 million. 
However, you're technology needs to be particularly innovative, the
acceptance rates aren't very high (I'm not sure of the numbers), and
even if you get the grant, funding isn't garuanteed.  Every few years
or so, Congress tries to cut the budget for this, so it's risky.

Also, friends, familiy, and fools are good people to ask for money,
but make sure they are well aware of the risks.

Unfortunagely, the ATP grant is cut, at least for this year.

Have you tried the SBA (Small Business Administration)? They have a
ton of excellent information on starting, managing and funding a small
business. Their web site is at: http://www.sba.gov.

Tom Belew (web developer - BizOffice.com)