depends on your strain... some ultra dank skunk will never work in a setup like that, no matter what you do. my strain (un)fortunately has a very light smell (which is probably due to some deficiency i have introduced) so i get away with very little in the way of oder.
one thing that helps with stealth is misdirection.
for example, a user unseen for awhile (picasso) put an air purifier on top of his cabinet. this gave the casual observer a rational excuse in their mind for why his cabinet was humming from fans.
an easy way to make tell tale ductwork going to the ceiling invisible is to cut boxes to fit around the duct over the cab. to the casual observer it looks like there are just boxes stacked up there... in reality, the boxes go around the ducts... fill them with Styrofoam or other insulation material and they will make exhaust rattle go away.
drier duct is nice to use for intakes and exhausts cause it is fairly easy to get and work with... but it isnt the best choice for the job. PVC piping makes GREAT ductwork and can be easier to hide. also, rather than using fittings for your bends, spend $20 and buy a hot air gun and melt the PVC to fit how you need it (easier said than done, takes a knack and care).
the smooth surface area of the PVC makes for better and cooler airflow. the physical nature of the PVC allows for a truly custom fit, which is crucial to a stealth grow.
larger PVC allows air to move quieter, BTW. a 2" tube might whistle. a 4" wont.
one thing is for sure, put a lock on the cabinet doors!