You, my large friend, need a steel bike. And Plus sized tires! Honestly, a great option at your price point is a Jamis Dragonslayer Sport. It was on my short list when I was doing my shopping. Definitely recommend getting a hardtail if $1500 is your budget (as it was mine,) you’ll get a much better set of components at that price point. Best of luck, I started a couple of months ago at 6’3″ 255 lbs, I’m now south of 240 and did my first race last weekend!