Sights depend on what you plan on doing with the rifle.
A lot of people enjoy open iron sights.
Nothing wrong with a holo sight or RDS for CQB. But you may have trouble with distance shots if anything bigger than a 1-2 MOA Dot.
A magnifier will help but adds cost.
Or run a 1-4, 1-6 or 1-8x optic.
Or if you just bench shoot, any regular rifle scope will work fine.
If your question was asking what brand then it comes to price range. What do you want to spend?
