Infrastructure suggestions

I am designing our new hosting solution and would like some suggestions on the best High Availability solution for our databases. This is our current use case:

80:20 Read : Write ratio
Currently all tables are MyIsam with a few (key) tables with FULLTEXT indexes
Hosting is in the cloud so would like minimal downtime for failover
Cannot change our existing applications to support multiple IPs to connect to

I was originally looking at using Percona Server Cluster and converting all the MyIsam tables to INNODB. But the constraint on the FULLTEXT index is posing an issue as I currently can’t change that in the application.

My other idea was to use Master -> Slave with server 5.6 and convert to INNODB (as 5.6 has FULLTEXT) - but not sure if this would be the best approach?

Any help or suggestions are very welcome.

Thanks for your time