I expect you will get a lot of advice here and it will be good advice. Usually people will recommend a specific boat that they like. It is important to recognise that these are always opinions and the people giving them may mean well but they will probably have different skills and objectives from you. No matter what boat you select you should keep in mind a couple of important points.
1. Your children will grow. Sometimes they grow frighteningly fast so if you plan to paddle with your children until they get bored or discover girls or boys you should get a larger boat than you need right now unless you don't mind buying new or additional boats on a regular basis.
2. Your combined weight is not all that low. Keep in mind that it is the total weight (boat, paddles, people, gear etc) that floats. This is called displacement. I won't bother getting on my soap box about that other than to say that the boat you buy should be designed for that displacement.
3. You will not notice any degradation in performance or handling In most receational boats so long as the boat is loaded within +10% -20% of the designed displacement.
4. If at all possible test some boats with everything and every body aboard and then test them with an additional 50 - 75 pounds just to see what it will be like a few years down the road.
5. The best thing you have going for you is that there are a lot of really nice boats out there and it is hard to go wrong anymore just so long as it is sized right for you.
The first paragraph also applies to me.