You seem to have answered your own thread Franco, I see your choice as either the Sigma 50/1.4 or the Canon 50/1.4 for the dollars you want to spend.
You could be very adventurous and go for the Zeiss 50/1.4, but you will have to focus manually and save a bit more, but people do that for Zeiss.
Sean loves his Sigma 30/1.4, that would give you a wider perspective, but than you would have a hole in your lens line up, if and when you do the "right thing" by your uncle.