I have 4 PAA brushes: Amber Aerolite, Solar Flare, Atomic Rocket, and Green Ray. They are all different (although they share typical synthetic brush features, I.e. soft tips).
The Phantom Aerolite knot is going to be the same as the Starcraft and Peregrino brushes except for size. The Roswell Grey knot in those two brushes has nice reviews.
Search for Peregrino in the Brush section and you’ll find some of them.
Among your 4 PAA brushes, which one splays the easiest? I like floppy brushes for face lathering creams, but am unsure of which PAA brush would best suit my preferences. Thanks.