If you are going to use spray cans, go with Rustoleum brand. Just my opinion, but that spray can brand is the best in terms of getting a decent looking finish, IMHO.
Since you're using MDF, go with an oil-based primer. After that, you can use the easier water-base latex paints for your base color or go with the enamel since you can get that in the spray can as well.
Rolling leaves marks and orange-peel. Spraying really reduces that problem.
As far as stencilling...I'd go with the spray can technique there too, just use very lite numerous coats, instead of 2 thick coats.
Make sure to let each layer properly dry and set before applying tape, or when you attempt to peel off your tape, it'll bring paint with it and eff up your day.