Atmos relies on directing sound and because the bass part of the audio spectrum is more diffuse, the bass part of the signal is filtered out either by your receiver or by the Atmos spec speaker itself. Consequently, it serves little purpose to spend money of full range speakers to use in Atmos service. It won't hurt to use full range speakers (except your pocketbook).
Panasonic TCP65VT60, Denon AVR-x6200w
Oppo UDP-203, Dish VIP722
NHT C4 front speakers, NHT C LCR center spkr
NHT Classic 3 surrounds
Velodyne Optimum 12 & DLS-5000R subs