If you already have spaces between your teeth then you have a spacing problem not a crowding problem so the chances of you needing any teeth removed is minimal. We don't like to pull teeth anymore and find that the patient is better off with a full set of teeth. Sometimes, wisdom teeth are...
With the teeth missing that you listed, it won't affect your Invisalign treatment. It works great for crowded incisors and you will love the results. You can always get implants later to fill in the posterior teeth (molars).
There are some competitors that try to use the concepts of Invisalign but they are usually sued for patent infringement. Invisalign is the leader in this technology. The ibraces arent really in competition because they use backets on the back side of the tooth so its not comparable. Whoopi...