i've always like Garden Watchdog on Dave's. it's come in very handy over the years when i find a new company i'm curious about ordering from. watch out for some of those nurseries in TN since there are a lot of them in that area and some go by many names but are really the same location in the same town. using the WD you need to read most of the feedback since they found out that some of the comments are padded to make them look better. WD has gone in and removed or noted those they found were fictitious and you should see that. which screams to me to avoid those companies.
some online websites will have a Garden Watchdog award posted on them from a certain year. they give them out for different categories like 'seeds company', 'trees', 'bulbs', etc.