Is the Canon 1.4 noticeably better than the Canon 1.8?
Yes. The 1.4 has MUCH better AF, better color, and far superior build quality. It's the sweet spot for the Canon branded 50mm lenses.
Which is better for Canon 60D? Canon 50mm 1.4 or Sigma 50mm 1.4 or Sigma 30mm 1.4 rather?
Should I go with this or wait until Sigma 50mm 1.4 will come at $350 price again or Sigma 30mm when it will be at its Nikon mount price $219?
It's up to you. 50mm is a bit long on a crop body and acts as a mild telephoto. It's good for headshots in portrait work, but often too tight to be a good walk around lens. The Sigma 50mm f/1.4 (which I own) is fantastic, but so is the Canon which I also have experience with. They each have their own look with the Sigma having wonderful, soft bokeh and a different color signature. The Sigma is a larger lens which can be a pro or a con depending on your outlook and both have known AF issues. The good news is that if you get a good copy of the Sigma (and mine was fine the first time around), it should stay working. The Canon's AF system is known to be temperamental and fail prematurely.
I cannot use the Sigma 30mm (5D here), but I hear it's a good lens. If I were you, I'd probably spring for that.