Don't worry about the sturdiness of frames. At your weight I wouldn't be worried about any bike, up to and including a super light carbon-fibre racing bike, as long as it had a decently heavy-duty set of wheels on it. The frame is not going to be a limiting factor and there is certainly no need to worry about going custom.
It sounds to me as if the Sedona was just too small for you. If that Hybrid/MTB setup is the style of bike that appeals to you, talk to your LBS about what they can supply and get them to advise you on fit. Unless your proportions are very unusual indeed, there won't be a problem.
Handlebars come in a variety of widths. It may cost a little extra to get them to set up a bike with wider bars than come as stock, but it's easily done.