Configuring Mango DB for processing Big DATA

Hello, Recently we moved to MANGO DB from MYSQL for our Big DATA. Overview : We have 275 GB(550 Million) of data per collection and we inserted it into mongo which occupies 140 GB(Storage Size including Index). Like this, we have 25 collections in a single database. Each collection has 30 fields, 16 are indexed. We daily imports up to 20(10 GB) million data to each collection and from this, we need to fetch 100 million data from our overall collection and we regularly require to do aggregate(group) from this 550 million records to generate live reports. Requirement: 1. Suitable Server Configure and tuning of Mongo DB ( Core & Ram & Version ) 2. Aiming to get Reports less than 1 minute.