For spring terminals, you would use a banana plug with a flex pin that can go in there. It is FAR more common to use bare wire, but if you are going to use a banana plug, you will want one with a flex pin that can go inside that spring terminal.
Silverback connectors have the quality you’ve come to expect from Sewell, including gold plated connectors and a heavy-duty casing. What sets Silverbacks apart is the unique dual-screw lock design. This connection will secure your cable more than a single-screw or open-screw design. Dual-screw...
You might want to spend some time reading and asking questions at diymobileaudio.com as well. They ARE into exactly this.
Frankly, every time I see Skar, I wonder how they stack up against JL Audio. I have a JL 12W7 and it really does blow me away.