Personally I wouldn't use the HRC ones as they are mainly designed for tracks and don't filter too much out.
Adding a high flow air filter can alter the A/F ratio and you could end up lean in areas of the map. You might need to get it remapped to be safe.
IMO the standard oem filters look pretty good, i dont think a hi flo air filter is going to achieve anything unless you have a PC, and de-cated headers. i would run oem filters in any case
Thanks for replys, there's some standard aftermarket filters on eBay for just under £16 each.. They any good? Or do u lot mean main dealer or David silver spares?
they will prob be fine, although make sure you change them regulary at service intervals dont think dave silva would charg much more, check anyhow
seems a bit dear id try a local supplier if you can dig one up. a non genuine filter is still ok, dont be afraid of an patent part
whatever you do,do not run HRC filters on the road,they have no filtering for dust/grit etc so will quite quickly make a mess of your pistons/barrels.