Best way to migrate from 1.7 to 2.0 across 4 nodes.

We have a cluster of 4 nodes that we want to upgrade from 1.7 to 2.0. Since these are < 1.8, we will need to do an uninstall and re-install, vs an upgrade. Was wonder if you had any recommendations of the easiest way to do this without any downtime, if possible? I read in your documentation to avoid doing a failover when changing versions. Is it possible to remove say 2 of the nodes, uninstall 1.7, install and configure 2.0. Then do the other 2 nodes. Once all nodes are upgraded, re-cluster them? Does this causes issues when clients are hitting the cache against multiple versions?

Thanks,