I'm looking to replace a 12" ReV Gen 1 rail with something that's a little more consistent with all of the other rails I shoot. That basically boils down to quad rails, but even if I go into this looking for non-quad rails, my other requirement is that the new rail be able to mount on a normal GI barrel nut. I'm trying to keep cost down, but the available options seem to be limited. I've come up with the following options:

C4 rail (which I love)
MI 2-piece FF rail
MI 2-piece FF rail MLOK

And that's about it. I already have a 12" C4 rail that's awesome, but I'd like to keep it where it is. A new C4 rail is pretty pricey and more than I'd like to spend right now, in a perfect world. The quad MI rail is about the same weight as the C4 for significantly less, but still nearly $200. The MLOK version is much lighter, and a little cheaper, but I also would need to find a MLOK handstop, so the price would probably be more than the quad rail version at the end of the day.

Any other rails I'm missing? I doubt I could get much for my ReV rail right now, so I'm not counting on any cost off-set by selling it. I thought I was going to be able to kill this rifle, but it continues to soldier on despite disrespect, neglect, and corrosive ammo. Pic for attention.