I agree with your selection. It would work great.
However for the computer-illiterate they will not care how fast a processor goes or how much ram is in the system.. what they see is a new shiney box *and* monitor.
If I were rebuilding a computer for my girlfriend - the first thing i'd start off with is a decent 22" monitor, and build within budget from there. You can usually pick up an LG or Benq for $170 range.
I think of it like selling a car - you can clean the interior up (what the person will see / use) but if the outside is old, scratched up and dirty.. it's not a good sale.
I would probably cheap-out a bit more on the PSU, there are other good manufacturers making PSU's other than corsair (and your girlfriend wont know the difference) OCZ, Thermaltake even Corsair has a cheaper non-modular line. I'd be in the $70 range, instead of $140 for that. To each his own though.
Perhaps buying used from the forum for the other goodies? I've seen a few 1156 boards kicking around, not so much the i3 cpus yet tho. Lots of ram deals for sure.
For overclocking, getting a Hyper 212 is the most cost effective, and could be done during the initial build, you can price match for around $22.
Remember to pricematch everything else also, you can save a good 10-20% on most items if you look around. It's the reason I use NCIX - most of the time they are cheaper than local computer distributors (not retailers - distributors)
That's just my opinion, good luck!