Where to get or create an Android Lollipop iso for x64 environment?

My question is simular to this question about iso for x86.

I am looking to dual-boot my Lenovo Yoga 3 pro with Android L and I need an x64 iso. I can not use an x86 as it is not able to install to my hard disk partitioned with GPT. Where can I find an Andorid L x64 iso?

I am willing to try to create an iso on my own. Does anyone know how to do this?