Don't know what your fitness level is or how hard you ride or what you ride over and into, but as a fellow large mammal, though a full size down at a 235 max (now down to 210) I can fully abuse equipment. Even large, I'm fit and ride very aggressively (with the occasional podium to prove it) so I feel qualified to comment.
Springs and shocks spare you more than the bike. They are actually one more thing to break or wear out so they won't save wear and tear on the machine. Bike damage has much more to do with how you ride than with your weight. A 160 lb kid with no sensitivity to the machine and a bad attitude busts up a lot more parts than I do. So will a large guy who plants his butt on the saddle like dead weight and just plows into stuff, or trusts indexed shifting to change his gears no matter how he's pedaling. That sort of behavior is what breaks parts, not being big and riding hard.
I don't think you need to look for anything special in a bike, just wide enough tires, something like a 38 or so and have a care for the bike. Soft pedal the up shifts. Get your ample arse up out of the saddle and shift your substantial weight going over obstacles, keep enough air in the tires to avoid pinch flats and don't do anything stupid or crazy. Or at least do stupid and crazy with a plan B and a care for the bike's survival.
For the most part exotic materials are wasted on us, but here's a guideline: Carbon and titanium and such are stronger than steel POUND FOR POUND but weaker inch for inch. So where the designer can take more room for a part these materials are every bit as strong or stronger. Forks and frames are a good example, for all but the raciest, lightest and most expensive ones titanium and CF forks and frames tend to be seriously over built. Parts where the size is constrained by the need to fit other standardized components are substantially weaker. Things like ti saddle rails or CF stems and handle bars are to be avoided. Of course that's a generalization but, well, generalizations are generally true.
The parts we endanger the most are the wheels. Good 36 spoke wheels preferably with some section to the rim and butted spokes with brass nipples tensioned well are the way to go. You can go with less, say 32 spokes and box section rims, but must be well built of good materials and you should be careful about what you try to run over (I'm guessing bunny hopping isn't going to happen so much). Again, technique is everything. You don't have to be nifty on the bike but you do have to get out of the saddle and use your legs for shocks coming off curbs or jumps and don't "stomp" the bike into the ground on the landings.
Like I said, even at 230 and riding trails hard on a cross bike, I don't break stuff and good 32 spoke wheels hold up and stay true for me. But it's more about how you ride than anything else. If you're staying on paved stuff and avoiding jumps and drops you shouldn't have anything to worry about. These machines have enjoyed about 140 years of evolution and the combined efforts of some of the smartest inventors and engineers on the planet from the Wright brothers on down. Ride and enjoy.
If you really want to stay conservative on the sturdiness side, get an ancient mountain bike, like from the 80s. Steel, rigid and solid but light, put smooth tires on it and ride the hell out of it. If you say more about your bike experience and riding intentions, we can get specific.