Can you please suggest which setup I shall follow for Redis?
You never can guess, if you're adopting scalable architecture i probably should check how much single redis can handle, and think wether you need a cluster or not, i've not worked with it to be honest, so it's just my "obvious" answer, also about sentiel - i looked what it is on the internet, and it seems to be some monitoring tool for the redis itself, so it's only up to you to decide wheter you need it or not.