AngWay "Sunup" and "Nextpush" can i use these to replace google play services to get my push notifications?
In short, no.
AngWay protonmail apps like protonvpn proton drive and stuff, and banking apps like capital one chime cash app self paypal mysynchrony twitter reddit discord youtube
None of these will work with Unified Push.
AngWay signal
The Signal app doesn't, but you can use Molly (an alternative Signal client) with Unified Push.