On another thread (I had the same question and had done a few searches) many said they trusted vanengelen. John Scheepers was also recommended on another forum. On yet another old thread someone mentioned colorblends.com

The prices are definitely the best at colorblends, and when I did a quick review search, they got excellent reviews. Has anyone here used them for allium specifically, and were you satisfied with the bulbs?

I got my Allium Ambassador bulbs from Colorblends last year and I was very happy. The bulbs were fat and produced beautiful flowers. I also purchased tulip bulbs and muscari from them and was happy with everything. The bulbs I got at Sam's Club, didn't do so well.