chasm54

There are many on here with experience of riding at your weight, and they may be more help to you than I, a mere 200+ pounder, can manage. But there are a number of things that occur to me.

You must find a bike shop where you can get some considered advice on what will fit. In the first place, your long torso has got a couple of inches shorter since you bought your last bike. In the second place, your surgery may have changed your posture, flexibility etc. and you need to sit on a few bikes of the right size to establish what sort of riding position works for the new you. So patronise a place where they will spend some time talking about your specific needs and don't allow anyone to just sell you what they happen to want to get out of their stockroom.

Second, consider what riding you want to do. You mention paved, bridle paths and off-road trails. Do you want something that will handle all of these? The Trek you've been looking at won't handle much of the latter, so you'd really have to think about a mountain bike. I'd suggest you'd only need front suspension since I can't imagine that at this stage you want to do serious downhilling. If you're thinking about paved plus bridle paths, then a hybrid with or without front suspension - if you get suspension make sure you can lock it out for road use - might be the thing. If you only want to go paved, the field is pretty much wide open and restricted only by what you want and feel comfortable on.

As for frame materials, your weight isn't really an issue, you can build a strong frame out of anything. But most of what you look at is likely to be aluminium or steel. Wheels don't have to be custom, there are some pretty strong wheels out there - the 26" Rigida MTB wheels I have on my touring bike would probably hold you, for example - but some of our heavier members will have more specific advice for you on that.

I can't really emphasis enough that the most important thing is to be comfortable on the bike. So establishing a riding position that feels right should be your priority, then look for the bikes that meet that need.