Replying to Rail dimensions help

Hey i'm having a rail professionally made by a local skatepark but i'm stuck on what i wanna get. i can't make it too high but i dunno if i can get enough speed. i want somethin where i can trick on and trick off of... i'm thinkin a flat down flat like 6 ft, 10 ft, 6 ft. maybe like 3 ft high at first dropping to 1 ft? (flat bar) maybe i should just get a flat rail to learn the stuf and practice it? but would kinks really make it that much better for like 75 more dollars? the flat down flat would cost like 200 and the flat would be about 125 or so. so any thoughts? height? length? dimensions? kinks?