I would just keep the std filter. I ran my car at stage 2+ with the std paper filter and it ran just fine. All these high flow panel filters don't flow much more air than the paper. I cant find the website but a test was done to compare the flow rates from after market filters of all types i.e cotton gauze, foam etc. The difference in pressure drop was 0.90% from the highest flowing to the paper filter. The main restrictions are down to the design of the intake rather than the filter itself.
I did have a K&N fitted but got a boost fluctuations. I refitted the paper filter and the boost fluctuation was gone with no detriment to performance.