I do both airbrush and paintbrush as the need arises and 99 times out of 100 Vallejo is my choice as it is a top quality acrillic with a strong pigment and good coverage.
THeir airbrush rage, Model air is noted for original chipset accuracy and you can use them with a paintbrush although a couple of coats may be needed with a paintbrush. They self level and dry quite quickly
I did try mission models recently with some Japanese aircraft colours and tested them with original chipset reference colours and noted that although they went through the airbrush very well and layed down like vallejo the colours mission models were off the mark from the chipset references with the blue-black of the zero cowling colour/anti-glare colour being more dark purple and the dark green late war navy paint having a distinct blue cast to it.
If you go with Vallejo you have more than one range you can pull colours in from to use with a paint brush, Model Color, Game Color, Game Air, Model Air, metal Colour etc.
you can see the airbrush paints in use on one of my builds here:
http://cs.finescale.com/fsm/modeling_subjects/f/2/t/180101.aspx
James