I recently gotten way into fly fishing with my daughter and want to get a boat. We will likely do a lot of trout fishing on the little red river in Arkansas but since that's a drive from Memphis we will likely do a lot of fishing in local lakes. All the guides up there use these locally built flat bottom fiberglass Supreme and Shawnee boats that are basically 20+' John boats. I considered getting one because they are just so spacious and stable for walking but 20' is a huge boat to store in the back yard so I started thinking a normal aluminum John boat would be better. I rented one today maybe a 10 or 12x36 or something and it was not pleasant. Not much better than a canoe and felt like I could tip it at any minute. I know nothing about boats. What makes a flat bottom stable? Length , width, both? Where do I need to be size wise to be comfortable walking and casting? Those supremes are like being on a dock. Would a 1648 give me the stability I'm looking for?