Sorry for all the questions guys, but ...
If I am forced to use wireless devices such as PW, why would I even purchase a unit like SB or mentioned YN flash?
I could just go by with regular non wifi flash units? I heard LumoPro is not bad?
So complicated ...
It's actually simple. No one is forcing you to use anything you're not comfortable with.
If you want to have the most flexibility, you can't do much better than using the native Nikon CLS system combined with radio triggers.
CLS, when used indoors or at short distances outdoors, works very well and it's super quick to set up. Pop up the on-camera flash, set the values in the menu, and go.
However when you have bright sunlight, obstructions, etc, then CLS is not as useful. I've used it in some cases where simple things like vegetation get in the way and I get misfires.
That's where radio triggers give you the utmost flexibility, although they take a little more time to set up and a little more investment in money and a learning curve.
They are tools. Buy the right tool for the job. If you are shooting indoors mostly, and want a simple set up, then a few new or used Nikon speedlights are all you really need with a D7000. If you want more flexibility and range, add radio triggers later.
OR - while learning the whole process, forget wireless altogether. You can buy a hotshoe sync adapter for the D7000, a couple cheap flashes with manual control, and use cords for everything. Or just use the optical sync functions built into many small strobes or monolights. The Lumopro LP160's are fantastic for this.
Personally I use a SB-700 I bought new, and a SB-800 I found used in Barcelona for €150. Both are work horses.