I can't comment on either tank specifically, because I don't have any experience with either, but I do own a NuvoAquarium Fusion 20 and a Lifegard 2.65.
The return pump of the Fusion 20 is enough for the entire tank. The 20 Peninsula should be the same size tank, but just with a different position for the back chamber. Not sure if the flow of water will reach everywhere, but I presume it should, it's a decent pump for that size tank.
My Lifegard 2.65 glass scratched relatively easily, which is a surprise.
So my recommendation in this case would be the peninsula, but just based off of very limited extrapolations.
I have a Nuvo 20 peninsula( as well as a IM nuvo 10 and a IM 50 lagoon).
The nice thing about the IM tanks are all the accessories that IM makes for them.
Even better is all that comes with their tanks,including a get lid.