Bricktown would definitely be your first choice if you're wanting to be a part of the young professional crowd. There's numerous restaurants downtown, night clubs, and the Ford Center for NBA and concerts.
Here's a link to the different housing projects down there
Residential
There's a handful of rentals, like Deep Duece. Some are loft apartments available for purchase.
The one downside to living downtown is that there's no grocery stores- however Sat morning OSU has a farmer's market. Other than that you'd need to drive a good 10-20 mins for groceries, depending on where you like to shop. There may be some convience stores down there now but I'm not for sure.
Some other areas with good food are the Paseo Arts District
The Paseo Arts District and Western Ave.
Visit Western Avenue - Oklahoma City's Unique Shopping, Dining & Entertainment District!