@ nikku_hot123
Let me clear it for you , I've already suggested the config , Reg proccy : 3rd gen i5 proccy have much OCing capabilities since 22nm still runs hot ! but still in future u can go for water cooler then OC .Always choose latest one . Only 1.7K more than 2500K
As for Motherboard : Asrock has very good build quality , Asus & Gigabyte you may face RMA issues since ASUS belongs to Rashi & gigabyte i dono since now many r facing issues with RMA , either you can go MSI if u have option in the mobo .
Cabinet : corsair carbide 400R gives u better look & Antec DF-35-AP is also same with looks as well as cooling u can put lot of fans