Do I need "New SQL Server Failover Cluster installation" to run Availability groups with manual failover?
If you want to just use stand alone instances - which is the most common method of implementing availability groups [stand alone to stand alone] - then you only need to do a stand alone install. So, yes, you can do the stand alone if that's what you're looking for.

It is possible to use a SQL Server failover cluster instance install to also work with availability groups but it is not required.