Platform migration with RAC conversion

Hi, I hope this is the correct community for this post.

We have a customer running EBS 12.1.3 with RDBMS 11.1.0.7 (single-node) on a Solaris zone.

They want to migrate their EBS to Linux x86-64, and in that process, move to RAC.  I've done platform migrations keeping the database as single instance; I've checked several documents on MOS, in order to come up with the necessary tasks to perform what the customer wants.

I know I could split the whole process into two main parts: 1) The platfom migration, and 2) The conversion to RAC, but that would require to have, in the target system storage space to hold the database in filesystem, and then ASM shared space to convert to RAC.