I would recommend to pay some attention to how easily you can move in different types of suits. How well the suit fits is a big factor, but you will find some suits allow more freedom of movement. You should, for example, be able to reach behind your head to your tank valve and have freedom in the legs to swim without restriction.
Many drysuit options can be added when you order or after you have your suit, so I'll start with some considerations that help you decide which suit to get. First, you may want to look at self-donning vs shoulder entry. Some divers like the self-donning in that they can get in an out on their own, but these tend to be a little more expensive. Second, the material choice is a big difference between different suits, as discussed above. Third, you should look at built-in boots vs neoprene "sock" suits where you use a separate boot over top. A last built-in to think about is latex vs neoprene seals. Latex are most common, but it's good to look at all your options before buying.
The second set of features are often either included, options, or can be added later. If you tend to carry extra stuff with you while diving, you will likely find that drysuit thigh pockets work a bit better than pockets in BCs. You often can order knee or butt reinforcements, if you think you need them. Many divers at the north end of the country will add dry glove systems, but you shouldn't need that in 50 deg +. Relief valves are nice but are relatively rare.