Any suggestions on a consumer lens with high zoom in & out and preferrably a low aperture so I could get those cool shots with über bokeh? I have a Nikon D5100.
Doesn't exist. Fast zooms are expeeeeeensive and even then they're still quite slow.
Your best bet (for a cheap lens) would be a long and fairly fast old zoom like a 70-200 f4-ish. Tons of them were made in the 80s, but pretty much none of them will autofocus on your camera. If you want AF (and better image quality) I think the rather slow (5.6 at the longest) 55-200 and 55-300 would be your best bet. They still sort of blur the background if you get close enough.
Long lenses compress the background (so it looks blurrier even if it is quite detailed like the above) and make it easier to fill the frame. The latter is important for the background blur.