Seeking better voice and text msg alerts (must work with Google Voice)

I want better voice and text message-notification ability. Specifically, want longer vibrate and ringtone periods for text messages. Most importantly, however, want ability to set a "mode" where an un-acknowledged (by me, the human) text of voice msg keeps ringing/buzzing/notifying until I look at it or acknowledge the phone-based notification in some way (even if it's as simple as pressing the power/display-lock button).

[Too often a text msg arrives at my phone, my phone gives a short/tiny buzz/beep that doesn't get noticed by me, and then someone who is trying to urgently reach me is wondering why I'm not responding.]

Any apps that serve these features on Samsung's Android (Touchwiz)?