Hello and welcome!
When I first started out I was 410 at 6'5". If I had read this forum before buying my bike I would have purchased the Specialized Hardrock. I've read many good thing about that bike for people our size.
The bike I bought was a Trek Navigator 2.0, and broke the rear wheel, seatpost, pedals, saddle, and lastly even cracked the frame. Now I must say Trek has been fantastic on their warranty and I had everything fixed or replaced and kept on riding. but like I said, I wish I had read this forum first and got the Hardrock at the time. I am now down to 280 and upgrading to a Trek 7.3 FX next week.
Jake