Instead of using screws on the side panel I would suggest using the Rubber Mountshttp://www.newegg.com/Product/Product.aspx?Item=N82E16811994036
They will fit perfectly into those holes and also save you from vibrations.
The fans you have chosen give you 44.7CFM @ 19.1dBA the only saver is the 4 in 1 pack for 19 bucks.
My suggestion to you would be to go for cougars.http://www.newegg.com/Product/Product.aspx?Item=N82E16835553005
That's 15 Bucks a piece but gives you 60CFM @17.7dBA
and plus the look really great.
and they come in lovely colors...