Factories that could make off-patent bricks? I'm quite interested in finding a factory that can produce a small-ish run of high-quality plastic bricks that I can use in my classes and possible to re-sell as stand-alone kits.  I only need a few different shapes, namely 2x4 bricks and 2x2 bricks, which are off-patent.  Does anyone know which factories, other than those owned-by/bound-to LEGO Group, have experience in making LEGO compatible bricks and would likely be open to producing another run?

Background

I run Ascendly.com which runs after school programs to teach grade school kids engineering.  My flagship course, Jr. Structural Engineering, uses LEGO bricks to build structures and to learn about the engineering process.  I only use a few bricks in the course:


2x4 bricks 
2x2 bricks
16x32, or larger, baseplates
1x2 bricks (optional)
1x1 bricks (optional)
1x2 45 degree slope (optional)


For any one class, I ensure all of the bricks of a certain size are a consistent and unique color. So, all of my 2x4s would be blue, and all of my 2x2s would be green, for example.  This keeps the students focused on the shape of the structures, makes it easier to see how the other students used their blocks, and avoids worrying about color aesthetics.

Buying bricks in bulk of any specific color is problematic.  

Related Question(s):


Where are LEGO parts made?
Are the molds for LEGO bricks maintained in house or is maintanance partly outsourced?
What kind of plastic are LEGO bricks made of?


Update
Just to add some context, I have good relationships with my two local LEGO stores, and they've helped me order about 50 pick-a-brick boxes over the last couple of years, but I'm hoping to find a more reliable and scalable source of building blocks.  Bricklink and LEGO are good sources for now, but I'm wondering if I find can a high-quality brick at 10x my current volume, something I'm positive the stores, and I suspect the LUGs, aren't in a position to accommodate.
I suggest calling Lego customer service (1-800-835-4386) to ask them about a bulk order. Professional "brick artists" like Nathan Sawaya buy their brick directly from Lego. The bulk prices are decent as well. For example, through the LUGbulk program, we got 2x4 bricks for about 9.6 cents each (these sell for $0.30/ea on the Pick-a-brick website).

Also, here is a long list of manufacturers who can do custom ABS injection molding: http://www.thomasnet.com/nsearch.html?which=prod&amp;cov=NA&amp;what=Custom+Injection+Molded+Plastics&amp;heading=95958385&amp;k=abs&amp;x=16&amp;y=9&amp;navsec=modify