First. PLEASE please please use sentences
A good return for limit is 2BB/100 - this actually a very good return, anything above it says you're a damn good player.
I've been told that NL players can make more/100.
However, limit players can usually multitable more easily (though it get's more difficult as you move up) and so can possibly even up the discrepancy between the two.
Limit and NL are VERY different beasts, what you should play depends on what suits you.
Most online pro's I've heard of play limit. But... there are some well known online pro's who make very good money from sng's or mtt's. These probably take more patience as you can go a lot of games without winning anything. Imaging playing 20 big mtt's where you last a few hours in each and fail to score in any.