You should have no trouble finding coral bells.
Most of their stock is at least somewhat seasonal but they likely have young plants in the greenhouse, maaaaaaaybe bulbs left over from earlier season but I wouldn't take your chances with those unless you know what you're doing. Otherwise, bulbs usually come in stock late winter to early spring.
I do not work at Merrifield Garden Center. I would suggest calling them. If they don't have them I am sure that they have some alternatives.
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