Playing semiprofessionally....rather part time

I have a full time job in nyc where I clear a decent living. My spending patterns are poor and I should have alot more int he bank but that is another story. I was considering playing during my nights online with an occasional trip to AC or Fox. As previous posts spoke about the swings in limit vs. no limit, I do agree that the mentality in limit is knowing specifically when to foldem. A significant raise cannot push your opponent off a hand and I believe that if you can perform this part of the game well then you can have a great edge in no limit games. With that said, I am looking to invest a portion of my salary into playing part time. I know you recommend 20 buy-ins for nl. If you are not playing 8 hours a day though, rather say 3-4 max, what would you recommend for that.