How do I choose which surgery I want

Well, that's something you need to be sure about; do you want to commit to a new way of eating for the rest of your life, or do you want to stay in your comfort zone with your current patterns?

The reason I want WLS is because I know by now that I need to be forced by physical limitation to make those long-term behavioral changes... I won't do it of my own volition; if I could, would have by now.

If you're not ready to make that commitment, then WLS is probably not a good idea. It's not a matter of "can I sustain the diet long-term?", it's a matter of "this is what I need to do to be healthy and I will do it".

If you're not at a point where you can make (and keep) that promise to yourself, then I'd urge you to think it through a bit more

Very good point.  I really think I am at that point.  I have tried it all and know that I too need forced limitations.  I can make long term changes but I need the reinforcement to get me on the path to change.  I used to enjoy physical activity before my knees started to ache so badly.  The doctor assures me that it is my weight causing the pain and that once I start loosing weight the energy and movement will return.  That alone will be a huge factor to keep me motivated and on track.