There is Fire Light, a H. paniculata which is hardy and not fussy in my area. There is also a H. macrophylla Firelight AKA Leuchtfeuer. Confusing, isn't it? Do you know which is being offered? Also, where are you? If it is still cold in your area and they are leafed out, you will need to keep them sheltered (at least when it is below freezing) in a building that stays cool but above freezing and with good light until it warms up; after frost danger is past for the Merritt's Supreme and until it won't get much below 30F for a H. paniculata.

How good the plants are at a grocery store will vary with both the supplier they use and how well they are cared for by the staff at the store. If they look healthy and the price seems good, I'd probably go for a H. paniculata Fire Light if you have a way to care for it until it can be planted out. I find that in my area, H. macrophyllas generally aren't hardy enough to bother with, though a few of the rebloomers might be OK.

I think my Aldi needs more space. They do not sell plants, probably because the size of the store is small. :o(

But do not necessarily let the plant's blooming fool you. Almost all (or all?) plants being sold are forced to bloom (by the plant wholesaler) early. In the first few seasons, the plant will fix itself to be in sync with your weather.

But this year, it was forced to bloom early because they wanted to ship the plant to stores by this date in bloom.

Keep them inside until all danger of frost has passed. Give it indirect light and make sure you do not forget to water it. Keep the pot away from vents. Note: if FL is also a mophead, both will need to be winter protected in the Fall in order to bloom somewhat reliably. Put winter protection in the Fall and remove it a few weeks after your avge date of last frost.