I also have long arms and long legs. I also have different bikes with very different sitting positions.
I have a stock 250 Rebel which sits me upright with knees bent. It is stable and easy to ride. It puts you in position to handle almost anything that comes at you. It is easy to get up on the pegs and off the seat if required. I ride it on dirt and trails around the farm with no problems. It is not particularly comfortable on long rides, but not bad, and is especially good for city, stop and go, riding.
I also have a HD 883 Hugger (wife's bike). It has a low seat and more forward bars. My knees are more bent and I have to lean forward a little also. It is not comfortable to me and doesn't really make it more stable or place me in position to react more quickly than the Rebel. I would not buy this bike for me, but it is the position a lot of bobbers end up at. My wife loves it.
My personal bike, customized to fit me, is a 1998 HD Dyna Wide Glide. It has lowered progressive rear suspension which lowers seat height. It has the standard raked Wide Glide front end with skinny front tire. It has forward controls which allow me to stretch my legs out, but make it impossible to get up on the pegs to ride aggressively. I have relatively narrow, 9" pullback bars that both raise the bars and bring them back closer to me, and align my arms almost straight forward from my shoulders . This allows me to sit upright, or to lean back on a seat backrest, or on a custom made padded bag that sits on the passenger seat for trips, sort of like sitting in a recliner.
I would not recommend this riding position to any beginners, or anyone that ever needs to go on dirt or gravel. It also requires a little more attention, and ability, in stop and go urban traffic. It is less stable, and less able to react quickly to traffic or emergency situations. However, it is the most comfortable position for me, especially for long road trips.
I also find all kinds of alternative positions to move to while riding for long times in order to change the stress on joints and muscles. I move my feet to lots of places other than the normal peg position. I put the back of my heel on the forward foot pegs instead of the bottom of my boot, in order to stretch my legs a little further. I place them up on the turn signal mounts for even more stretch. I put them back on the passenger pegs and lean forward to relieve back stress. Some people used pegs on crash bars to accomplish the same things, but I just don't like how they look on the Wide Glide. All of these positions make you less stable and less able to react quickly, and should not be used in traffic or city driving. They do offer more comfort, and the ability to ride longer before having to stop for stretching on long highway trips, but at the price indicated above.
Be sure you are capable, and fully able to control your bike from these positions, and while moving to or from these alternative positions, before trying any of this. Again this is not for beginners, timid bikers, unstable bikers, or less confident riders. I am sure Mr. Duckster would have a cow if anyone in his Motorcycle Rider Safety Classes tried it. Oh well, that is why I not only own a Rebel, but I am a Rebel on a Harley. Each rider is different, with different ergonomics, and no one type, style, or position will fit everyone. You have to find the position that fits you, both your body type, and riding ability. Ride safe, and be comfortable.