I was thinking about getting an Alpine MRD-M1005 amp for my 15" L7 it runs at 2-ohms do you know if that would be enough?

Your L7 has dual coils, each at 2 ohms. You could wire this several different ways. In series, parallel, or separate (depending on the amp you choose). The Apline MRD-M1005 is a mono amp with 700W rms power at 4 ohms and 1000W rms power at 2 ohms. Since it is a mono amp, it is not possible to wire both coils in such a way to get 2 ohms overall impedance. You could wire in series for 4 ohms or parallel for 1 ohm (bad idea with this amp - you'll fry it.) If you wire your sub's coils in series (4ohms) this amp will run your sub at 700W rms, 4ohms. Should sound great as the spec for your L7 says it will operate nicely between 200-1000W rms. In addition, you won't run any risk of blowing your sub since the power supplied is less than the sub's max rating.