I think using your cursor as an example isn't especially convincing but that aside I understand the point you're trying to make. You'd be surprised at what you'll "see" as a huge difference that in real terms isn't as large a difference as you think.
Also 30 fps is pretty good for a lot of games, depending on the quality settings you have and the game itself/the engine it uses, as with proper frame transitions it'll still seem very smooth. Perhaps you're a big fan of constant action FPS games or games with a lot of twitch gameplay, I personally can't stand titles like those

So maybe the 120Hz is worth it for you, I play games and in a way where I really doubt the doubled monitor refresh rate is going to make much of a difference to me. (For instance SC2 at 25 FPS actually still looks very smooth)
And I really don't like considering SLI or CF set-ups as the scaling is usually very uneven, some titles scale really well, some don't at all, overall I don't think the gains are worth the cost and trade-offs you make for it.
That all aside, and getting back to the OP's build I don't think a CF set-up is really necessary for 1920x1080 gaming is it? Most titles will scale just fine with only 1 card and the CF gains will probably be in a range where the gains are just fps numbers and won't make a noticeable difference in his actual gaming (such as going from 70 fps to 95 fps, he's not going to notice the difference for the most part).