The two things that I highly recommend for a hair system are:

1) Highlights

2) A professional cut-in

Both of these go a long way toward that "textured" look you are talking about.

The highlights are self explanatory, but in my opinion a lot of guys underestimate the realism that a professional cut-in provides. Especially with a full cap.....it's 99% the same as real growing hair (unless the ventilation is funky) so pretty much any stylist can do a cut in. Go to a good one that knows how to texturize and the results can be spectacular.

I'm going to try to post pics of my latest full cap this weekend. It is by far the best cut, style, density, etc of any piece I have ever had. I have probably gotten a dozen compliments on it.

I will even try to include illustrations of the things that make this unit look so good. Aside from the cut, highlights, density, etc. there are several little tricks that add amazing realism.