I just discovered iLog which not only does what you want, but it has one of my most missed features: a nag beep/vibrate for missed calls/SMSs. It's on Cydia, and the name recently changed to MobileLog, which isn't yet on Cydia.
I believe it's 5 minutes, only repeats twice and is the same ringer/SMS sound. Not 100% sure on the last bit. In any case, too little, not configurable enough and not often enough for me. 😉