Best recoil spring for a Marui M9 ?
 

This is exactly what I need. Right now I tried 3 different aftermarket recoil springs on my Marui and all of them feel rather weak. I mean if I compare it to the recoil spring I have on my WA 1911 they're simply 2 worlds apart.

Now I'd like to know from personnal experience what would you consider to be the best option out there. That is keeping in mind I have a metal slide and frame from Zeke installed on mine.

Thanks in advance and I do hope anyone can help me out with that.