First of all, there's a supplement industry listing available online of companies it says are GMP certified.

More information on the FDA rules, which were arrived at after negotiation with the supplement industry.

Note that many firms (notably the smaller ones) don't have to comply with these manufacturing safe practices until 2010, and there's also a possible exemption that can be granted so that companies don't have to verify the nature of all their products' ingredients to exclude adulterants (a particular problem with products imported from abroad from places like China).

Beyond checking that the companies you buy from comply with the cGMP code, it's important to check on the claims that they make for what their supplements are supposed to do, and that these claims are validated by quality scientific studies and not solely by unreliable personal testimonials. The basic setup under DSHEA, which allows companies to make questionable claims for their products in a general way, is untouched by the new FDA rules, so it's still largely a jungle out there and we have to be vigilant about what commercial products we buy.

Incidentally, I'm wondering why you're trying to avoid soy and magnesium stearate in supplements - is this because of personal experience or due to warnings you've seen on websites?

For evidence that compliance with "good manufacturing practices" doesn't necessarily protect consumers, here's a new report on Ayurvedic medicines.

"The current study included 193 products randomly selected and purchased over the Internet. The researchers found that 20.7 percent contained metals. The rate in U.S. manufactured products was 21.7 percent, and in Indian products, it was 19.5 percent.

Not surprisingly, almost 41 percent of rasa shastra products had a greater prevalence of metals, including high levels of lead and mercury. "Several Indian-manufactured rasa shastra medicines could result in lead and/or mercury ingestions 100 to 10,000 times greater than acceptable limits," the researchers wrote.

Seventy-five percent of the products claimed to be manufactured under Good Manufacturing Practices."

Note the comment from a spokesman for the American Herbal Products Associciation (an industry trade group). The AHPA emphasizes that heavy metals in the Ayurvedic medicine products are from hard-to-avoid soil contamination. Yet these potentially toxic metals are deliberately added to some Ayurvedic "herbal" products and it's apparently happening in the U.S. as well as abroad.

It's one thing to consume such products without good evidence that they help - far worse to risk heavy metal poisoning as well.

Here is a link that might be useful: Ayurvedic medicines

If you are looking for products, I get some of my items from I Herb online. They have quite a selection. I also use Thorne supplements, which is free of what you mention. My naturopath uses them. Just put Thorne products in a search window, and look for a place that has the prices you want.
Darlene