P180b Case Fans for Max CFM vs decent noise: which are best?

Sorry if this is in the wrong section but i am going to start ordering parts for my new build and want to know if there is a differance between getting 120x25mm case fans for a Antec P180b case or if getting 120x38mm fans is better? Anyone have any experiance with the following and is one better for the money than the others?

The choices are: Silverstone FM121 (120x25mm)
Scythe S-Flex (120x25mm)
Yate-Loon (120x25mm)
SilenX iXtrema pro (120x38mm)
(other worthy case fan)
The case already comes with three stock 120x25mm fans. Should I bother replacing any of them for better performance/noise or just get two more. One for the front (intake) and another for the middle (over the video card(s))?

Thanks in advance!

i would try it with the stock fans first they have 3 speeds soo can you can try slow and silent or fast and noise see what the temps are like and if fast makes any differnec. if i was going to add a fan i would would add 1 120x25 in the lower part of top section sucking air in but you can only put one there if you arnt using the hdd slots.