The Toda cams work very well on the k20 and are generally reliable,
If you pick BC cams make sure you get them from a UK supplier (Japshop, TGM etc) as from the USA the profiles will be different.
The US profile is more like a std Type R cam so will not give the gains.
When i was racing Time Attack, Paul west (TP on the forums) had exactly the same engine spec as me in his civic but with toda A3 cams, he was easily able to pull a couple of car lengths on the straights at Silverstone, i would then easily pass under braking or around the corner though , it was going to be my next job after fitting a final drive.
it will cost about £1500 for the kit inc fitting