About your budget, make some room for accessories like riding shoes, gloves, maybe small handlebar and/or saddle bags for tools, keys etc, maybe talk the shop into giving you some loot like bottles and cages. I don't remember where i read it but get the best frame you can afford and be prepared to upgrade the components after after getting comfotable with the bike and knowing what you want. Same for shoes and pedals, Shimanos 3'd from the bottomn PD-M520 is a great workhorse pedal, and if you want a platform on one side the PD-A530 has the same mechanism but only on one side.
For mountain bikes the wheel strenght issue isn't so big, as they are made for jumping off stuff and generally being beaten around but the lower spoke count wheels on some of the pricier bikes might be a bit too soft for a big guy. You're only 195lb so maybe they would do too.
For you riding, look at medium knobby tires, the most aggressive ones will give too much resistance, and the slick ones maybe a bit too little grip.
At this price level, hardtail mountain bikes are the ticket, you *can* get a full suspension bike for $1000 but it won't be suitable for the kind of riding you plan to do. Look at the Trek 4500 or Kona Cinder Cone. In a certain price range most bikes have the same components, of course there are lemons too.