Hot cams are the only ones that are technically drop in. Most go with the S3 and have been happy from what I've read. A Web cam requires stiffer springs and hardened rockers due to the lobe profile being more aggressive.
Alba doesn't use Web cams anymore in their Stage 2 kit. They use Hot cams as I just inquired about 6 weeks ago before my motor was getting built. Web pulled their offering for awhile in order to fix hard start issues related to the de-compression mechanism. They are now selling them again but it seems Alba hasn't pursued offering them again, for whatever reason.
08' Blackbird XX - IPS tuned/built 53whp woods terror (710cc/10.5:1, Hot Cam S3, Ported Head, Pro design filter, Barker's, PCV, HD Clutch, + much more)