Bikes for larger people?

I suggest that you begin by going to your local bike shop and test riding a few bikes of each catagory. See which you prefer to ride rather than what you think would be more interesting to you. Years ago, I was bitten by the MTB bug and went out and bought one. I thought that riding trails woule be more interesting than riding the road. It didn't work put that way. I was back to riding the roads within two months.

Actually there are several hundred brands and models of MTBs and road bikes that you can choose from. Narrow your choices down a little and then let us know what you are interested in and we can give you insights to those specific bikes. Your request is a little open ended and I really don't know where to start in answering it.

Keep in mind that at your size, and with your leg strength as you claim, wheels will be an Achilles' heel on just about any bike you buy. You will probably want to start with something that has larger rims and higher spoke counts--closer to a mountain bike. Also, when you start riding, it may be tough but to go easy on your wheels and drivetrain, you'll want to train yourself to a higher cadence (pedal revolutions) in a lower gear. I've been on a few tours with some larger folks who pedal slow in high gears, and they're always breaking spokes and having other mechanical issues. The folks who pedal faster in lower gears don't tend to break as much stuff on their bikes.

You might consider the 400 GVW Husky or Worksman industrial bikes.
Note that the rims are thick steel, and spokes are 11 gage 0.110" .

huskybicycles.com

worksman.com

I might be a little late in this thread, but anyone who might be interested-Yuba Mundo cargo bikes are designed to carry heavy loads. They can handle 400+ lbs of cargo alone so their wheels and frame are just about as sturdy as you can get. They have an upright riding position that is incredibly comfortable and easy to maneuver.

Check out yubaride.com.