SP or AF when using a fan filter

I have a 650D case where I plan to use the rear fan as intake and for that reason I will also use a filter. Since the filter will be a bit of a resistance would it be better to use a SP series fan rather than an AF series fan?

I'd use an AF. Then the best method is to build a filter that is away from the perforated metal grille of the case and is larger in surface area than the opening itself by as much as you can get. Think of an air filter on a car. They're pleated. This increases the surface area of the filter to more than the area of the carburetor throat. If you just slap a foam filter directly on the round opening, close to the fan blades, it will restrict the opening and partially starve the fan; no matter if it is an AF or SP. See this thread/post for more:

 

http://forum.corsair.com/v3/showthread.php?t=118043

I've been thinking of getting this filter -> http://www.amazon.co.uk/120mm-Aluminium-Mesh-Fan-Filter/dp/B004CL8EOM/ref=cm_cr_pr_sims_i

Get a 140mm, at least (180mm or 200mm would be better), and stand it off the surface by an inch by making a box to mount it on and/or do the same with the fan inside the case. Keep the filter and any other obstructions, including the perforated metal, away from the blades and the throughput increases dramatically. It's almost like adding another 100mm fan without all the noise.

As I wrote in one of the other threads I decided to start with using the filter mentioned above together with an AF120 Performance Edition and if the result is too bad I might trying to build something on my own like you suggest.