I was pretty much in your spot a few months back with an extra 20 lbs. I was thinking about a Phat cruiser with 3" tires. If I could have gotten that bike with at least 21 gears I would be riding it today. I wound up with a cromoly hybrid and had to replace the back wheel with a stronger wheel.
If you go to 29" wheels, they will need to be even stronger than 700c wheels. Meaning there is a good chance you will have to have a rear wheel built for it.
I went with a rigid fork because I didn't want to spend the money to get a better quality suspension that I wouldn't bottom out. If you do go suspension get one that you can lock out for road riding. I also replaced the suspension seatpost with a regular seat post, which translated to easier to pedal, but less comfort.
Don't worry about hitting the ground from the seat, I have never been able to do that from most of my bikes (except the recumbents). A lean to the side or a curb work just fine and are second nature now. (I have a 29" inseam and am 5'9")
From what I have been reading and what I have seen the frame is the strongest part. Off road usage could change that, but for on road wheels are much more of a problem. I was breaking a spoke every hundred miles or so.
Last edited by Fangowolf; 11-29-12 at 04:27 PM.