As far as I know, reputable sellers do not sell bulbs you mentioned in spring. Lilies sold in spring are prechilled.

Yes. I should think finding them in bulb form at this time year virtually impossible. And if you do, they are not worth spending money on. Spring blooming bulbs like the ones you mentioned are sold now, but started in containers or "in the green" with foliage showing and often buds and blooms. If your weather is suitable, they can be planted now or added to containers, etc. Lilies and other summer blooming bulbs are typically purchased now and they do not require any chilling period. Just plant them, for later season blooms.