I’m a novice kayaker with an Old Town Vapor 10 rec kayak. I mostly kayak on man made lakes which have some light to modest waves when wind kicks up but are pretty flat most of the time. I like the stability of my kayak and the size of the cockpit as I’m a bigger guy.
The thing is that I’d love to take my dog (a 60 pd collie mix) and occasionally my wife on the lake with me. I’ve been thinking of adding a canoe to my fleet but don’t know what to go with. I’m mostly concerned with stability, but I also want something that has at least a 750 pd weight capacity in case we’d decide to take it camping.
I’ll probably be paddling solo 90% of the time and even when the wife is along, she won’t be doing much aside from sight seeing and I’m concerned a longer boat might be too challenging for me to handle solo. I have zero canoe experience aside from capsizing one in boy scouts 20+ years ago. Frankly, I’ve been wary of them ever since then so I hope someone can steer me in the right direction. 
Thanks!
next boat
One of the reasons kayaks are popular is that they can be handled by novices with no training. A canoe will definitely handle you and your wife and a dog. It is not that hard to handle a 16 canoe solo. You just have to paddle from amidships. You can even use a kayak paddle if you are already comfortable with it. It will be much more seaworthy than a 10 foot kayak.
no canoe will hold 750 lbs
nor does it need to… You have listed a max of 450 lbs ( apologies to your wife… I likely overestimated) Gear should not weigh 300 lbs. Ours for two weeks weighs 70.
Capacities are often listed with six inch freeboard as the measure. Performance capacities are much less… measured as sinking the craft to the four to five inch waterline and leaving 8-10 inches above water.
This gives you way better performance. Otherwise you might as well buy a log. Even 18 foot long canoes don’t have performance capacities of 700 lbs. 16-17 which you are looking for hold less, Google Archimedes Principle.
You are asking one boat to do a lot. Canoes are versatile but to solo a 17 foot boat is challenging in a breeze and to solo an 20 foot (which your capacity criteria call for) just about impossible. The Old Town XL will do well
But its 105 lbs.
Yeah, not really 750
I came up with that # after browsing some online and thought, the higher the weight capacity, the better. I don’t think we’d top out at over 450 even with the dog, camping gear and a cooler full of food.
Are there any certain models I should look for, or hull shapes? Like I said, I have no experience so stability/safety is my primary concern. Speed is a very, very distant afterthought.
Any general-purpose, two-person canoe
Since you don’t specify a need for certain traits, you’ll do fine in whatever general-purpose canoe you can find, though I’d recommend a decent used canoe of any major brand over any of the cheap plastic ones that are carried by the big-box stores. Most general-purpose canoes are actually pretty hard to tip over if you follow a few simple rules (the rules aren’t all that inconvenient, and people here can help you out with that). If several people start suggesting models to consider, you could end up with a pretty long list of contenders. An alternate first step would be to find a few models that are available to you on the used market, and then ask if people think they are suitable.