Recently bought a 2010 model of this car, and it was pretty stock. Went through this phase 
Since I was using a Pioneer pre (7450SD), I didn't have the option of a DVD player so I went with an LCD in my rear-view mirror. It fits OVER your existing rear-view mirror, is wider, and is slightly darker.
The total cost was 4500 (1500 camera + 3000 rear-view mirror/LCD). The performance is decent, however during bright summer days, the mirror is kinda useless unless you give it some shade (very reflective, so you can barely see the LCD).
There are other options.. Like installing a DVD player. The chinese version of Honda's own navigation system costs about 22k if I'm not wrong. You can buy used Pioneer etc DVD players cheaper. Depends on what you want. If you want to install a high-ish end sound system, I'd suggest stick to the rear-view thingy.