I have a cannon EOS 60D with an EF-S 18-200 lens. This lens is not good enough for clear pictures at the extent of its zoom. Which lens 400-600 would offer the best value for money: picture quality, speed and lastly portability? Thanks!!
In the 400-600mm range there really isn't much that can be described as "... best value for the money."
You either pay for the best (Canon EF 400mm f/2.8 L IS II or EF 600mm f/4 L IS II) or you settle for value (any of the Tamron or Sigma Contemporary or Sports 150-600mm f/5-6.3 offerings, or the EF 100-400mm f/5-6.3 L IS II). The Sigma 120-300mm f/2.8 is somewhere in between (On your APS-C 60D it gives a FoV equivalent of 190-480mm on a FF camera). The EF 400mm f/5.6 L that has been around since the early 1990s is another low end option.
None of the above are what might be considered portable. The 400/2.8 is the fastest and has the best picture quality.