Avoid Gurneys. The same company that owns them also runs Michigan Bulb, Breck, Spring Hill and several other companies. They all should be avoided. Their plants are very small and quite often their perennials don't make it through their first season (no matter how well you take care of them). Some of the companies (like Spring Hill) have a "lifetime" replacement policy but that is such a hassle and it puts you one year behind in your garden. You are much better off just buying good plants.
This time of year a lot of people are planting bulbs for their spring garden. Two places that have excellent quality bulbs are John Scheepers, Inc. and Van Egelen, Inc. Both are run by the same company.