Wow, good questions all in one. I live in North Dallas and I' ll tell you about my location, which of course I think is the best! Prestonwood which is at the intersections of Arapaho-Campbell/Hillcrest-Preston area. In your price range you can get a wonderful home with at or above your square footage expectations, updated with a pool and more. . Prestonwood, the neighorhood, is in the center of everywhere, we are close to the Dallas Toll, 635,I75 and the George Bush. (I am assuming you know Dallas with these land marks)In other words, the center of everywhere. The schools are fabulous. RIchardson school district which is the best large district in Texas. Even if you don't have kids that's good for resale. Also close to shopping. The area is well established meaning it kept it's value when the market dipped. There are various subdivisions with the area, Prestonwood, Northwood Hills, McKamy.
I lived in the Lakewood section of Dallas over 20 years and love it also. It's closer in the downtown and is closer to the arts district, Whiterock Lake (inner city lake built in 1922) etc. The home prices are much higher, you won't get the house you are looking for there.
If you would like, shoot me an e mail with a few more parameters and I'll set you up on an e mail gateway that will allow you access to MLS listings and you can get a feel for a few of the areas and the pricing.
Best of luck