I think it will depend on how you plan to hold the vertical grip. Will you be fully gripping the vertical grip in a manner similar to the pistol grip or will you be using the more tactical style "thumb-over" grip that Magpul encourages? I prefer the former grip method for the type of shooting I do (informal target shooting) so I went with a Mission First Tactical React Short Grip. I chose the MFT grip over the Magpul because it is just a bit taller, which allowed enough of my small finger to grasp the grip to satisfy me. For me, the Magpul left my little finger hanging which I don't like.
Have you considered a bipod foregrip? I've got the FAB Defense G2 and it's a good combination of both features and very sturdy, plus not as heavy as I'd been told.
I use the UTG D Grip Bipod. It is very high quality all aluminum and the swing down bipod is also all aluminum. I love mine and it has a cool "OH WOW" factor as well when you hit the button and it swings down.
I have the BCM (Bravo Company) angled short grip on 2 of my rifles and I can't see ever taking it off - they're light, sturdy, and perfect for the way I use them.