SU carb air filters

[alexG]

Anyone had any experience of good alternative (but still in keeping) options to the old narrow style wire and guaze types?
   Having just had the car on the rolling road with poorish results on a fully rebuilt engine, I was told to throw away whats on the car and get something with better breathing!
   Like:
   http://www.knfilters.com/search/product.aspx?prod=56-1630
   
   Or of course could just go for ram pipes like;
   http://sucarb.co.uk/air-filters-ram-pipes/ram-pipes.html
   
   Obviously not much dust/dirt filtration with latter.