I need a better way to haul a rifle than on the seat.  I see there are a few different models out there to choose from, I'm just wondering if somebody has personal experience with one or any better ideas.

I've had every one in your pics, they all have their pros and cons, the roof mount, Great, but sometimes hard to grab your gun in a hurry. The floor 2 gun mount is what I use now, works great, but sometimes gets in the way. the horizontal ones are pretty good with any shorter guns, I've knocked a gun off with a tree branch more than once, my fault for forgetting about it, but it still happened. picture of mine.