You're within the weight range for the boat; it should be sized all right for you. Might be a little short on footroom.
The inazone is a pretty solid downriver boat; I've done big water class IV in one and felt very comfortable. You can surf, spin, and maybe start to throw ends in it. It should serve you as a good boat definitely for the first year of paddling, and maybe for the first three years or so depending on your learning curve. I'd say go for it, and see if you can talk the guy down to $375 or $400. $425 isn't a bad price though, as long as the boat is in good shape.