Post forum and Signature Help

[frendzinc]

I want so that when user is 7 days old and has 5 posts then and then only he can
use signature...

and other thing is.. same for posting in some forum..

i can speciafy in X forum is user is Y old days then only he ca post..
or if he has X posts then only he can post..

where can i find mod for this ??