NoSQL expert required for a migration and scalability project -- 2

The project consists of migrating from a PostgreSQL database into a NoSQL database. We're looking for a NoSQL expert (MongoDB, Cassandra, CouchDB, etc) who can help us to determine the project's viability, time and cost estimates. The main goals for this project are: - Stability - Scalability - Reasonable complexity The goal is to identify which technology suits our technical needs better and study its cost. Please include in your answer details about the approach you would follow to study the viability of this project and any relevant question you have. To make sure you read the post, please include the result of this operation in your answer: 2*21=? Thanks.