price sounds fair, if it's good mechanically and runs well. check out rear shock, if stock it's prolly blown or ready to blow. check swingarm over for stress cracks.
i'm 6'3" also and find my z to be a pretty comfy machine. depending on tuning and gearing powerband is like a light switch. i consider mine trail friendly, although at low speeds when i ride with the kids it does tend to foul plugs unless i keep it in a lower gear so it can rev a bit. i like the way it handles, but couldn't say how it compares to an r.
bought mine for $700 in pretty rough shape, around $2500 invested so far.
good luck!
86 tri z - might be nearly done throwing money at it! (good thing, the hondas are getting jealous!)
86 250sx - old reliable
83 atc 70-new project for me and the boy
another 82 110
a bunch of golf carts for the wife and kids
-gone but not forgotten-
82? 110 - why did i sell it??
84 225dx - meh, it was a pile