Originally Posted by daisymtc

Power supply OK.
Some fan does not come with screws, like those black extra value one.

One fan at the back for exhaust is a must. The one at the front for intake is up to you. It does enhance the case ventilation.
As ordering online, personally will pay extra £1-2 for another fan in case you need it. You will found your local store/ maplin sell them double of the price at ebuyer