The DX is fine, I've had mine forever, its a great trail trike, I'm 6'8 also and the only modds I've done to adjust the bike are wheelspacers and fourtrax250r bend bars on all my bikes. That bend bar has the highest rise w/out going with risers.
"If you are going to piss like puppy, Don't Get Off The Porch"
Trikes:
84' Suzuki ALT185 (old Orange)
85' Yamaha 225DX, piped and spaced ( First Girlfriend)
Quads
87' Yamaha Banshee, built and very very fast (The Whore)
01 Yamaha Raptor 660, built and piped (The Beast)
03 Suzuki Vinson, 26's and piped (The Crowd Pleaser)
Once apon a time:
85' Tecate 300 alky flattacker, 6 in over swingarm, 88 Suzuki 500"Quadzilla"PIA , 91 Yamaha Warrior Built and Modded. (luved that Baby Tank)