what length ladder bars?

i'm giving up on my cow tracks, and before i order any ladder bars and shocks i'd like to here from your guys set ups and experiences. the question is they are offered in a couple different lengths. which one's do you think i should use. 32" 36" and why. also what length shocks to use that will fit without going into the trunk. 12" length on the coils or 14". the car i have is a 69 dart with aprox 440hp and auto trans that i leave off a brake. 10.5 slicks in the rear with a 9" 4.30 gear. glass fenders, hood, and deck. no back seat and a pair of kirky fronts. 6 point cage. thanks don