If you want to do a multisite cluster as few nodes as you have, I strongly propose that you should have same amount of nodes on both site. Otherwise you will need at least same amount of data disks on both site and using same configuration for those is some kind of nightmare.
Use at least 4 node (2+2) with site_rep + site_search 2. Add option that both sites have at least one copy of data. If you can add more indexers then you can add one more copies on primary site if you want.