Hardware requirement for SQL BI

Hi,

i have started working on BI solution on SQL Server 2017 and Power BI. i have to create BI solution for Financial Institute where i have to perform ETL for lots of files and generate BI reports. pls guide what could be best hardware configuration for Server based on your experience. no of user will be 100 concurrent. i will be using alwayson for HA.

Thx

iffi