Hey Gadgetmann, I'll give my half cent on your questions.
1. I am 6'2" and find my '94 RT/10 very comfortable. I am not as built as you (170 lbs) but for leg room I think there is plenty. I tend to sit with my butt pressed against the back of the seat though.
2. I live just north of you in Vancouver. You're welcome to drop by some time for a test drive in my car if you're interested. I've heard about people complaining about the car being really leaky but I am very impressed with mine. I had a Porsche 911 Cab that was very leaky and the Viper isn't leaky at all. I had it out the other day and the skies opened up, it was pouring cats and dogs and I didn't get a drip inside the car. When I wash the car I usually get some spray inside because inevitably the water gets under the cloth windows. But it's minor and not a problem. I don't have the hardtop, just the softtop but it seals great. There is a space between the top and the very top front of the windows that you can actually see through but rain never comes in there. Without any rain trough along the roof though you usually get a bit of a drip when you open the doors. Pretty normal for sports cars though in general.
3. There is probably a list somewhere that someone has or could make (Jon B?) that would give you a checklist of things to look for when buying a Viper. A few obvious ones are to look for cracks (paint splitting) on the hood, pulsing driving that may be caused by leaking intake gaskets (usually just caused by improperly adjusted throttle bodies), unusual smells (coolant, fuel, etc.) which could be caused by leaks or improper burping of the system (over-heating potential), etc. These are just things that I have heard of or experienced myself with my car. As always, after owning a car for a while you would be a much more aware buyer.
If you end up narrowing it down to one or two and want a last minute check I could probably be convinced to pop down for a nice drive to Seattle to take a look at them with you...assuming you find some locally. Good luck and although I am not an expert I would be more than happy to answer any questions for ya.
