as with any GPUs, they come with the cooling unit (fan & heatsink) attached so there is nothing extra to buy unless you're intending to modify it

for the R9 290, a good 600W PSU should be sufficient

You have GTX760 ady? if not go for R9 290

SLI will eat alot wattage, you sure prepare at least 800W PSU for stability

I think you should list out your current spec first

if you do SLI, you have to change your mobo to any SLI supported mobo, like MSI Z87-G45 Gaming

Those fan can be replaced with this :

Here the link..

Go for R9 290 RM1449

SLI you need motherboard that usually cost 400 at least
And better psu

i will suggest getting single strong gpu instead of sli/cfx 2 mid-end gpu to save hassle.
You may gain decent performance but drivers, games compatibility may also be the issue. Furthermore, u need to spend slightly more on mobo and psu to ensure the multi gpu setup works.
Precise calculation needed to make sure sli/cfx is worth it.

On what resolution do you want?

Yes, it should be. Your max power draw for the GPU should be 400W max. But try getting 80+ Gold rated PSUs though, like the Corsair RM650 or Seasonic X650. The CS650 will need to draw 600W just to pump 480W due to it's 80% efficiency.

Oh wait it is. Sorry sorry paiseh. 
Was thinking of another model hahaha. Yes the CS650M will do you fine