Hate to double post but I had to leave in a rush for work and forgot to mention some things.
I don't have an i7 but from everything I've seen over @ XS, there haven't been to many i7's that have run "cool". They've all been pretty "warm" (very loose usage of the word

), I doubt that a single 120 rad would give acceptable temps. It would probably be best to at least consider a 2 x 120 rad as a "minimum requirement". If your really strapped for room, Swiftech has stackable MCR120's on their site that should give a little less cooling power than a standard 2x 120. Another thing to consider is that smaller cases already have worse air flow than the bigger "closet cases" (as I call them) so this also has to be factored into rad selection for acceptable temps.