An intermediate binding is exactly what you need right now. These bindings typically have a DIN range of 3-10, which means they're designed to hold your boot securely at moderate speeds and forces while still releasing predictably when you fall. That balance is key—intermediate bindings give you reliable retention without being so stiff that they won't release when they should.
It's tempting to buy an expert-level binding thinking you'll grow into it, but that can actually be dangerous. Expert bindings have higher DIN ranges (8-16+) and are built for the forces generated by racing or aggressive big-mountain skiing. If you're not generating those forces, the binding may not release properly in a fall, increasing your injury risk.
A good rule of thumb: match your current ability with maybe one level of room to grow. Since you're already pushing into black terrain, an intermediate binding will serve you well and can be adjusted as you improve—just have your DIN settings checked by a certified technician each season.