I have come up with this reply because I have read more about comparisons between GTXs and Quadros. Everyone is talking about cooling (a topic that I hdn't thought about previously). Because I am going to use the GPU for heavy work (hours of rndering, etc.) I need to be sure that it is not going to break down.
In terns of money, I think these are my limits, so I have to be sure that I do the right choice. I'll wait for more opinions.
Thanks in advance.