GRM put on racing pads and ducting and they were pretty satisfied with the results. Save your brake money and go racing, then decide what you need. Who knows, a lot of people spend a ton of money only to find out tracking the car was a little more than they really wanted to deal with.

I don't think the results are in here but I have them somewhere if you want them. This covers their ducting install and is a good read in general for you;
http://grassrootsmotorsports.com/pro...onda-civic-si/