gouache and possiblities

i've been researching grounds for the gouache paintings again-
i would like a different color ground....
i found some ideas that could work maybe
if i can get to experiment--- i keep hoping someone says 'oh i got the perfect thing for you, it's exactly what you need'
but so far not in america

so this is some of what i been thinking of

all involve work and are an expense i really don't want or need
 1) 300# watercolor paper and acrylic inks- downside..... the ink won't be perfectly even, it will be a mottled look
2) casein on mat board- downside..... this would be a 'lean over fat' which is not good
3) acrylic gouache on mat board- downside......the pigments aren't as lightfast as i would like

all i want is an approximate 300# HOT PRESS -100% cotton rag with a few completely lightfast colors......
dark blue
dark red
deep purple
dark green
and a sorta moody selection of various grays

is that too much to ask?